What are linked genes ?
Linked genes are genes that are located on the same chromosome.
Hence they are passed down together, and their phenotypes are often found together. An example of this would be the genes for red hair and freckles, which you usually see together in people.
That is a basic overview of what they are. If you'd like to learn more, I encourage you to watch this video by Bozeman Biology:
Hope that helped :)