SRM = Standard Reference Method. This is a measurement method to calculate the colour of beer where 2 SRM is super pale yellow and 40+ SRM is pitch black.
IBU = International Bittering Units. Another measurement, used to determine the level of bitterness in the beer. Something like a standard light American lager has about 8-10 IBUs, and a super hoppy double IPA can have 90+ IBU.
ABV = Alcohol by Volume.