Nerve compression is when there's pressure put on a nerve by a bone or an intervertebral disc.
This occurs when the spine becomes misaligned for some reason (faulty movement patterns, injury, chronic muscular tightness) and one of the discs between the vertebrae get squeezed on one side so that it bulges out the other side.
If the bulging puts pressure on a
spinal nerve, then you’ve got pain.
Nerve entrapment is when a nerve is caught or pinched by the soft tissues.
For example, the sciatic nerve (the largest nerve in the body) runs down through the buttocks and can become entrapped by the piriformis muscle when that muscle is very tight.
This can result in pain down the back of the leg and is commonly referred to as piriformis syndrome.