What does make 1 front mean in knitting?
One front is an increase stitch done this way:
Pick up the horizontal strand with the left needle from front to back between the last stitch worked on the right needle and the next stitch to be worked on the left needle.
Then, insert the right needle into the back of the loop, and knit it.
KFB stands for Knit in Front and Back. It's also known as an increase (not a make 1). Generally KFB's are done on a knit row though I have seen patterns where they're done on a purl row. Youtube has a bunch of videos showing how-to's you might find one there. I find videos make more sense than text when working out some knitting methods.