How does crossing over affect variation

Crossing over is the exchange of genetic material between nonsister chromatids in Meiosis I, so they are essentially scrambling their genetic information. Recall that meiosis produces gametes, two of which get combined to create a zygote, so two cells that have employed crossing over combining will lead to increased variation from generation to generation.

This is giving me a headache i have asked others and they don’t know it either