In English law if you get injured and it's somebody else's fault you are entitled to compensation.
In the vast majority of cases that involves accidents, like being run over by a car, or tripping up on a paving stone, or whatever.
In some cases however it involves deliberate injuries. That deliberate injury is of course a criminal offence of assault or grievous bodily harm, or whatever, so the perpetrators can be prosecuted.
Prosecution doesn't generally get you much, if any, compensation. You have to claim your own compensation. And very often the sort of people that will go around committing these offences do not have any money to pay you any compensation anyway.
Therefore the government has set up the criminal injuries compensation scheme, which is designed to pay out compensation to people who suffer as a result of criminal conduct. The conduct might be something as blatant as a physical attack or something like trauma brought on, maybe many years subsequently by something like sexual assault, or whatever.
A lawyer will guide you through the process to make sure you get the compensation that you need.