What is the policy of "don't ask, don't tell"?

the military seems to have a problem with homosexuals, so basically it means, the military doesn't ask if a recruit is a homosexual, and the recruit doesn't offer the information

...but if the military finds out, one way or another, that a person is homosexual, that person will be fired. (No longer allowed to serve in the military.)

When people are advocating for the repeal of "Don't Ask, Don't Tell," they're advocating for allowing homosexual people to serve in the military openly.