You can use short rows when knitting socks you use them to turn the heel – they take place of the heel flap & gusset.
Short rows are partial rows. Instead of working an entire row, a portion of the stitches in a row are worked. Multiple rows are worked to create shaping.
Short row heel
Short rows for a heel are worked over a decreasing number of stitches, then worked over an increasing number of stitches. The number of stitches on the needles doesn’t change, just the number being worked. The extra rows stack up where stitches continue being worked. Stitches are wrapped to prevent holes and the wraps are picked up and worked with stitch to hide them.
There are many ways to knit short rows, including s-w-s (slip, wrap, slip), and the German short row, both of which I’ve outlined here.