Can someone explain the purpose of #ForeignAid ?

I know it sounds obvious, but is there a ££ return for our £14.3 billion investment? 

Why do we have rough sleepers and restrict our pensioners heating for :-

Afghanistan 🇦🇫 £355 million
Nigeria 🇳🇬 £110 million
Yemen 🇾🇪 ffs £77 million
Syria 🇸🇾 £63 million

????????