The terms do get used interchangably, mostly by those who don't know the difference but, technically, there IS a difference. It doesn't really refer to the tools or components used, it has to do with methods and care in the work. It's largely done by those using turret or progressive presses, few of them are striving for tiny groups so more demanding - and slow - techniques are meaningless to them.
"Reloading" is what most of us do. We strive for usable ammo in quanity, in the least amount of time and/or as inexpensively as possible. In application, it commonly means picking a charge out of a manual, testing enough to see if it's safe and then cramming some cases full to have fun blowing them down range in casual "target" shooting or practice.
"Handloading", as the name implies, means there's a lot of hand craftsmanship and, usually, some specialised tools to aid the process. It usually indicates that great care has been taken in selecting a limited number of cases and uniforming them in several ways for the absolute best cosistancy. They are then precisely loaded and carefully tested to find the best possible accuracy obtainable. So, in "handloading", the stress is on accuracy, not high volumes or time/money saved.
Whichever approach we choose, it should best suit our needs, neither is automatically "better" than the other. A reloader who spents a lot of meticulus time uniforming cases that will be tossed out in rapid fire by a limited accuracy weapon will be wasting a lot of effort with no gain. On the other hand, a long range target/varmint shooter who picks an "OK" load before quickly cramming together a single box of ammo for a day afield without doing all he can to insure accuracy is wasting the opportunity to make his few shots count.
The names really do, or did, mean different things, and each has a practical correct application. But, like so much of our language, through common misuse the words have been degraded so much it no longer matters very much which one we use.