Short rows are used to create shaping in a garment; usually on the heel of a sock or the neckline of a sweater. It allows you to work one part of a row several times to create more fabric in that area.
It's a technique that can seem intimidating to beginners, but in reality, it's really just a skill that is yet to be learnt. Everything is teachable.
There are a few ways to work short rows and each one leads to slightly different results in the finish but the most popular method seems to be the German Short Row.
German Short Row