Exposure Lock (AE-L Button) is the abbreviation stands for Automatic Exposure Lock. It is useful using automatic and semi-automatic shooting modes.
Exposure Tutorial Part Three: What is ISO?
#Nikon’s history in pictures: from the Nikon 1 rangefinder to the D70s DSLR
10 Things to do with your new camera + a Free Checklist! These tips are useful for anyone and everyone who owns a DSLR camera