What is the difference between double-ampersand (&&) and semicolon (;) in Linux Bash?

Question

What is the difference between ampersand and semicolon in Linux Bash?

For example,

$ command1 && command2

vs

Answer 1

The former is a simple logic AND using short circuit evaluation, the latter simply delimits two commands.

What happens in real is that when the first program returns a nonzero exit code, the whole AND is evaluated to FALSE and the second command won't be executed. The later simply executes them both in order.