That highly depends on the type of media you get digitized.
Video Tapes:
Each video tape will have its own DVD. 1 video tape = 1 DVD
Film Reels:
Film reels will be combined into one or more DVDs.
Audio Tapes:
Each audio tape will have its own Compact Disc (CD). 1 Audio Tape = 1 CD.
Photographs and Negatives
All photos will be placed on a CD. Each image will be an individual JPEG file.