We use reported speech to tell a person (Julia) what another person (Sam) has said. Depending on when Sam made his statement, we adjust the tense of the reported speech.

Example:
Sam: I like pineapple.
to Julia: Sam says he likes pineapple.

When the reporting verb, in this case “says” is in the present tense, the following verb (likes) is typically also in the present tense.
This would be appropriate to use when Sam has just made this statement, and someone standing right next to him, Julia, did not understand. If the reporting verb is in the past tense, then the following verb is also in the past tense.