What’s The Point Of A Head?

I have the fender Mustang IT twenty five cause I love the effects and it’s a good practice amp but I’ve been thinking about upgrading some hardware. What is the point in getting a Cab and Head combo stack like this one? Like what does the Head actually do or help with besides look awesome. I will also take any suggestions for good practice / play amps for a not very sound proof bedroom or any suggestions really that would be good for anything from Blues to Brit-Pop. Thanks!

I have the fender Mustang IT twenty five cause I love the effects and it’s a good practice amp but I’ve been thinking about upgrading some hardware. What is the point in getting a Cab and Head combo stack like this one? Like what does the Head actually do or help with besides look awesome. I will also take any suggestions for good practice / play amps for a not very sound proof bedroom or any suggestions really that would be good for anything from Blues to Brit-Pop. Thanks!