A boolean algebra expression such that a ∨ b is true when one or both terms are true, and false otherwise.

Truth Table

1 ∨ 1 = 1
1 ∨ 0 = 1
0 ∨ 1 = 1
0 ∨ 0 = 0

Plain English

When people say "or" they usually mean logical exclusive or.

eg: You can throw the ball or hold on to it. You cannot simultaneously throw the ball and hold on to it. You must do one xor the other.