There are 4 products.
The Raspberry Pi B+ is a credit-card sized computer that plugs into your TV and a keyboard. It’s a capable little PC which can be used for many of the things that your desktop PC does, like spreadsheets, word-processing and games
The Compute Module 4 IO Board is a companion board for Raspberry Pi Compute Module 4. It is designed for use both as a development system for Compute Module 4 and as an embedded board integrated into end products.