A Brief Look Let's take a look at the back squat!
There are two primary versions of back squatting, both useful, but for varying reasons.
You have high bar back squatting, often seen in the olympic weightlifting community, and low bar back squatting, commonly seen around the powerlifting community.
Essentially, the placement of the bar during a back squat affects the joint angles involved and thereby influences how force is applied to the low back, legs and hip musculature.
So depending on whether you are using the low bar or high bar form, the placement of the bar will change the lifter’s necessary positioning to maintain the bar/mid-foot relationship and affect which muscles are used.
The picture shows a basic understanding for how the bar placement will recruit different muscles and apply different forces. ENJOY!