Legal requirement Vs Statutory requirement

What's the difference between a legal requirement and statutory requirement. (In the context of the UK jurisdiction, but explanations about other jurisdictions would also be welcomed}

I googled it and ended up hurting my head. I appreciate that the terms are used interchangeably but the pedantic side of me would just like to know..

Explanations Like I'm Five would be greatly appreciated. (Also posted in r/ELI5)