To ask a really boring question?

[seaside849]

Hoping someone can just give me a simple answer.

If you have a small car accident where someone pulls out in front of a car and the other goes into them, do you have to call the police and prosecute or just exchange insurance details?

Insurance. It's highly unlikely they would be convicted of dangerous driving, and that is the only point in contacting the police.

If nobody is hurt just exchanging details is fine. Take photos and number plate though in case they try to say there is more damage than the reality. You need to inform police within, I think, 7 days.
If anyone is injured you need to call police.

Just insurance

Unless there were other circumstances at play, such as a possible criminal offence like drink driving etc, then it's fine to just exchange insurance details. This happened to me. The other driver admitted liability. He simply hadn't seen my car. The insurance company paid out.