Short for “electronic press kit”. This is just a computer or web version of an artist’s publicity material: biography, pictures, showreel, news, etc. There are loads of sites with advice on compiling a good one, including ours.

Press Kit Strategies for Singers & Musicians
The main goal in creating a press kit is to generate interest in an artist and the music they play. A press kit includes background information, photos, samples of music, a listing of past and future gigs you have scheduled, and any other pertinent information.