NERV is a special organization under the UN with the purpose of safeguarding the planet against monsters curiously called Angels through the use of bio mechanical semi-sentient robots called Evangelions. It was formerly known as Gehirn, a UN Research Agency. It was reorganized into Nerv once Nerv HQ and Tokyo-3 became fully operational. There are several global branches of Nerv besides the main headquarters under Tokyo-3 itself.
The Nerv Logo is half a fig leaf covering its name, with the motto "God's In His Heaven... All's Right With The World" forming the quarter circle on the bottom. The motto comes from Robert Browning's poem "Pippa Passes"