Hi I Have these equations and I don't know and understand what each of them means. Can someone help me?

$$\tag 1 v=v_0+at$$ $$\tag 2 x=x_0 + v_0t+\frac{at^{2}}{2}$$ $$\tag 3 v^{2}=v_0^{2}+2ax$$ What does each of them do at certain distance, acceleration and velocity? At class the teacher didn't explain us how each of these formulas work.