Illustrator gives a tool to Scale objects (shortcut-s) but you can do the same thing by transforming the bounding box. I am just curious about how differently it works and in which conditions it is used to scale the objects?
There are three primary differences between the scale tool and the bounding box. The difference is actually quite big a whole category of recurring questions on this site could be avoided if people knew this.* This is even more important with rotate tool versus bounding box rotation by the way. Ultimately it makes you a much better illustrator user because so many how do I do that thing becomes possible once you do.
The bounding box only allows you to scale towards opposite corner or center of object.
The scale tool allows you to define the point around which to scale.
This feature can be very useful if you want to do specific perspective effects with repeat last etc. But its even more useful in combination with the next feature.
The Bounding box allows you to initiate scaling at the abstract bound corner
The scale tool can be initiated anywhere.
This feature in combination of feature 1 allows you to specify 2 points on object one and 2 point on a second object matching size (length etc). This is extremely useful for reversing mistakes, for making isometric shadows etc.
Bounding box only appears on full objects.
You can scale parts of objects with the scale tool.
As a bonus feature it also allows you to measure scale in conjunction with the numeric input dialog.
* In fact until you master the scale rotate and skew tools quite a few very basic things are outside your reach. But ultimately i can only teach you things you are aware of and ask about.
There doesn't appear to be any functional difference, other than that the scale tool allows you to be more precise in your scaling.
Note that when using either the scale tool or just transforming with the bounding box, the "Scale Corners" and "Scale Strokes & Effects" options apply.
The "cup" in this example had the exact same 50% scaling applied, one with both mentioned options checked on (right) and one without (left). This may be another thing to be mindful of when scaling.