A:Answer The 70-200mm f/4 Canon EF lens should work fine on the T7i camera. It is auto-focus and has image stabilization. A very nice lens. All "EF" lenses will work on most all crop or full-frame sensor Canon DSLRs. "EF-S" lenses will only work on crop sensor cameras, NOT on full-frame. The T7I is a crop sensor camera.
So, with a 70-200mm zoom mounted on the T7i you should experience a zoom range of 112-320mm lens. Multiply 70 by 1.6 and 200 by 1.6. Will be a fairly long zoom but still a bit short if you're looking for an extreme zoom range. Will be much better than a shorter lens, though, for shooting birds and other wildlife that you can get closer to...for shooting childrens' plays at school, sports, even portraiture if you have the working distance. If you're looking for a "normal" zoom lens, a lens that is often recommended is the 17-55mm EF-S. This lens is kind of the "holy grail" for Canon crop sensor cameras. It equates out to a 27-88mm lens...very useful "normal" range zoom. It is often stated as being "L" quality in an EF-S lens. Mind you, though, that an EF-S lens can not be used on a full-frame sensor camera...in case you possibly see a change in the future to full-frame. ;) The 70-200mm EF lens will work on either size sensor camera.
The 70-200mm f/4 is a fine lense. Just know what your getting and what you will be using it for. Best wishes!