See it like when you compare two things and the result is true or false.
If a=1 and b=1 then both are 1, so a and b (are both set) is true. If a=1 OR b=1 then at least one ofem is set, so the result is true when at least one of them is not zero.
Example of usage:
if (mousedown(1) or mousedown(2)) = true then ...
is diffrent from
if (mousedown(1) AND mousedown(2)) = true then ...
If a=1 and b=1 then both are 1, so a and b (are both set) is true. If a=1 OR b=1 then at least one ofem is set, so the result is true when at least one of them is not zero.
Example of usage:
if (mousedown(1) or mousedown(2)) = true then ...
is diffrent from
if (mousedown(1) AND mousedown(2)) = true then ...