mange, manges, and mangez

[pulsar topaz]

I'm wondering how am I supposed to know when to use words like: mange, manges, and mangez. I dont understand the difference; could someone explain.

[cyan surge]

these are verb tenses

je mange - i eat
tu manges - you eat
il/elle mange - he/she eats

nous mangeons - we eat
vous mangez - you (pl.) eat
ils/elles mangent - they eat