In computer programming, what is a conditional?

Conditionals essentially test for true and false.

For instance, in python:

if 1 > 0:

   the code does something.

Since 1 is greater than 0 the conditional is true, but if the if statement is false, for instance:

if 1 < 0:

   the code does something

else:

   the code does something else

The if statement is skipped because 1 is not less than 0 and the else statement runs.