It is very important that the chain on the chain saw always remains very sharp to constantly perform well. You can sharpen your chain saw with a round file or a jig without actually removing the chain from the chain saw. You can also remove the chain and use a specialized electric sharpening jig. The chain saw sharpening jig will assure that the cutting faces of the chain will maintain the proper cutting angles. Every cutting face is well balanced to maximize the chainsaws cutting efficiency. The correct hand sharpening method probably will produce a better result, but electric chain saw sharpeners are faster, especially when you are sharpening super dull chains.