What happens if an electron collides with another electron?

We know that electrons always repel electrons. But, if somehow they collide, then what will happen?

I found a related question of above one in Quora.

An incoming electron can instead make them both bounce away.

Two free electrons will bounce off each other unless perfectly aligned. In which case, both explode and produce photon(s).

I agree with his first statement. But, I am in little bit of confusion of second statement. I know that if electron and positron collide, then they will form photons.

But, none of his statement answers my question.