what's the difference between endo and exothermic?

Answer 1

endo sounds like into
exo sounds like exit
thermic = having to do with heat.

If a process absorbs heat, it's endothermic
If a process releases heat, it's exothermic

If you are boiling water over a gas flame, the gas flame is exothermic - releasing heat, and the boiling water is endothermic - absorbing heat.