A closer look
A tense verb is a verb form marked for time: past, present, or future. She walked puts the walk in the past; She walks places it now; the future leans on the helper will.
Tense is time itself; has walked adds aspect, a nearby system.
A quick picture
She walked home yesterday is past tense. The ending -ed on walk signals that the walk already happened.
I will sing at the wedding next month is future tense. English often borrows the helper will here, since the bare verb alone cannot reach forward in time.
People also say tense to mean the whole time system of a language, as in English has a tense system. That is the same idea viewed from further back: each tense is one form a verb can take, and together those forms make up the system.