Graphic explains the nature of pyrocumulonimbus clouds. A specific cloud generated by forest fires that is capable of generating its own weather system causing other wildfires and even fire tornadoes

A teacher explains to pupils how to use masks against the spread of the new coronavirus, at a primary school during the first day after summer holidays amid the COVID-19 pandemic in Athens, Greece, September 14, 2020. Thanassis Stavrakis/Pool via REUTERS

A teacher explains to pupils how to use masks against the spread of the new coronavirus, at a primary school during the first day after summer holidays amid the COVID-19 pandemic in Athens, Greece, September 14, 2020. Thanassis Stavrakis/Pool via REUTERS

Buddhist nuns explain a woman about the process of recycling plastics in Yangon, Myanmar, September 4, 2020. Picture taken September 4, 2020. REUTERS/Shew Paw Mya Tin

Ricoh Industry executive Kazuhiro Kanno explains the company?fs system to remotely monitor production equipment at its printer components factory in Atsugi, Kanagawa prefecture, Japan July 13, 2020. Picture taken July 13, 2020. REUTERS/Naomi Tajitsu

Founder of the Ministry of Fun Santa School, James Lovell, explains how to decorate a face visor during the class, in London, Britain August 24, 2020. REUTERS/John Sibley

An instructor of the training center explains the structure of an EUV machine to the media at ASML Holding, in Tainan, Taiwan August 20, 2020. REUTERS/Ann Wang

A clay figure of the microscopic view of the coronavirus made by Edgar Alvarez, Colombian artist and creator of "I explain it with plasticine," is seen on a sidewalk, amidst an outbreak of the coronavirus disease (COVID-19), in Bogota, Colombia August 7, 2020. Picture taken August 7, 2020. REUTERS/Luisa Gonzalez

Edgar Alvarez, Colombian artist and creator of "I explain it with plasticine," takes pictures of his clay figure of the microscopic view of the coronavirus, which he put on a sidewalk to photograph, amidst an outbreak of the coronavirus disease (COVID-19), in Bogota, Colombia August 7, 2020. Picture taken August 7, 2020. REUTERS/Luisa Gonzalez

Edgar Alvarez, Colombian artist and creator of "I explain it with plasticine," models a clay figure of a Venezuelan migrant, amidst an outbreak of the coronavirus disease (COVID-19), in Bogota, Colombia August 7, 2020. Picture taken August 7, 2020. REUTERS/Luisa Gonzalez

Edgar Alvarez, Colombian artist and creator of "I explain it with plasticine," takes pictures of his clay figure of a Venezuelan migrant, which he put on a sidewalk to photograph, amidst an outbreak of the coronavirus disease (COVID-19), in Bogota, Colombia August 7, 2020. Picture taken August 7, 2020. REUTERS/Luisa Gonzalez

Edgar Alvarez, Colombian artist and creator of "I explain it with plasticine," wears a face mask as he models a clay figure of a Venezuelan migrant, amidst an outbreak of the coronavirus disease (COVID-19), in Bogota, Colombia August 7, 2020. Picture taken August 7, 2020. REUTERS/Luisa Gonzalez

Edgar Alvarez, Colombian artist and creator of "I explain it with plasticine," wears a face mask as he takes pictures of his clay figure of a Venezuelan migrant, which he put on a sidewalk to photograph, amidst an outbreak of the coronavirus disease (COVID-19), in Bogota, Colombia August 7, 2020. Picture taken August 7, 2020. REUTERS/Luisa Gonzalez

Edgar Alvarez, Colombian artist and creator of "I explain it with plasticine," wears a face mask as he models a clay figure of a Venezuelan migrant, amidst an outbreak of the coronavirus disease (COVID-19), in Bogota, Colombia August 7, 2020. Picture taken August 7, 2020. REUTERS/Luisa Gonzalez

Edgar Alvarez, Colombian artist and creator of "I explain it with plasticine," wears a face mask as he takes pictures of his clay figure of a Venezuelan migrant, which he put on a sidewalk to photograph, amidst an outbreak of the coronavirus disease (COVID-19), in Bogota, Colombia August 7, 2020. Picture taken August 7, 2020. REUTERS/Luisa Gonzalez

Jorge Enrique Salgado explains how he built a replica of the Eiffel Tower on the roof of his home in Havana, Cuba, August 6, 2020. Picture taken August 6, 2020. REUTERS/Alexandre Meneghini

WASHINGTON, D.C.- AUGUST 6, 2020: Senator Maggie Hassan (D-NH) questions Chad Wolf, acting Secretary of Homeland Security, who appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Senator Ron Johnson (R-WI) questions Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Senator James Lankford (R-OK), speaks with Senator Ron Johnson (R-WI) during the hearing where Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Senator Kamala Harris (D-CA) questions Chad Wolf, acting Secretary of Homeland Security, who appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Senator Josh Hawley (R-MO) questions Chad Wolf, acting Secretary of Homeland Security, who appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Senator Rand Paul (R-KY) questions Chad Wolf, acting Secretary of Homeland Security, who appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: A board with photographs from the protests in Portland, Oregon is placed behind Chad Wolf, acting Secretary of Homeland Security, who appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the deployment of federal agents during the protests. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: A board with photographs is displayed behind Chad Wolf, acting Secretary of Homeland Security, who appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: The tweets from Portland Mayor Ted Wheeler are displayed behind Chad Wolf, acting Secretary of Homeland Security, who appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Senator James Lankford (R-OK) questions Chad Wolf, acting Secretary of Homeland Security, who appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Senator Maggie Hassan (D-NH) questions Chad Wolf, acting Secretary of Homeland Security, who appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Senator Maggie Hassan (D-NH) questions Chad Wolf, acting Secretary of Homeland Security, who appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Senator Maggie Hassan (D-NH) questions Chad Wolf, acting Secretary of Homeland Security, who appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, on screen, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Senator Rick Scott (R-FL), in foreground, listens to Chad Wolf, acting Secretary of Homeland Security, who appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Senator Rand Paul (R-KY) questions Chad Wolf, acting Secretary of Homeland Security, who appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Senator Rick Scott (R-FL) listens to Chad Wolf, acting Secretary of Homeland Security, who appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Chad Wolf, acting Secretary of Homeland Security, appears before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

WASHINGTON, D.C.- AUGUST 6, 2020: Senator Rand Paul enters the hearing room where Chad Wolf, acting Secretary of Homeland Security, will appear before the Senate Homeland Security and Governmental Affairs Committee on August 6, 2020 in Washington D.C. to explain the use of federal agents during protests in Portland, Oregon. Toni Sandys/Pool via REUTERS

Thurston County Auditor Mary Hall explains the ballot sorting and security process at the Thurston County Ballot Processing Center in Tumwater, Washington, U.S. July 23, 2020. Picture taken July 23, 2020. REUTERS/Lindsey Wasson

Chen Hsiu-Hsi, the associate Dean of the Department of Public Health from National Taiwan University explains the use of a negative pressure isolation room to the media on the Explorer Dream cruise ship in Keelung, Taiwan, July 26, 2020. REUTERS/Ann Wang

UPDATE updates publish date Graphic explaining the route and rites of the annual haj pilgrimage

A healthcare worker explains a man how to lean back to collect a swab sample from him during test for the coronavirus disease (COVID-19), at a drive-thru testing site in Ciudad Juarez, Mexico July 17, 2020. REUTERS/Jose Luis Gonzalez

Gonzalo Esteche, an employee from a local club prepared as a human foosball pitch with zones for each player to avoid physical contact, explains the rules of the game to an amateur player wearing a face mask, during the spread of the coronavirus disease (COVID-19), in Pergamino, Argentina July 4, 2020. Picture taken July 4, 2020. REUTERS/Agustin Marcarian

Denver City Council member, Amanda Sawyer, uses her phone to explain to residents, Martinez Anderson (left), Kenneth Crowley II and Kenneth Crowley Sr., what will happen at an upcoming city council meeting after Monday?s planned council meeting was canceled based on concerns with social distancing after Black Lives Matter groups organized citizens to sign up for public comment and bring up concerns about the Denver Police Department during the meeting at city hall, in Denver, Colorado, U.S., June 29, 2020. REUTERS/Kevin Mohatt