Just joined this forum and the ranks of a handgun owner.... so pardon me if this seems like a stupid question to all you veteran shooters out there but I'm not exactly sure what a "hot Load" is or means.... and why anyone would want to shoot this type of ammo?

I have a S&W .38+P/.357 so would a "hot load" in my gun be a .38+P+??

Maybe this is a bit simplistic but if you want to shoot more powerful ammo....why not just buy a bigger gun?