What is the difference between gene silencing and gene knockout?

Both gene silencing and gene knockout are techniques used to prevent gene expression. The main difference between them is the level of repression. Gene silencing is considered a gene knockdown mechanism, which generally reduces the expression of a gene but does not completely eliminate it. In contrast, gene knockout completely erases genes from the organism’s genome; thus, there’s no expression of those genes at all.

Gene silencing is often considered better than gene knockout in research because gene silencing methods allow the study of essential genes that are required for the animal modes to survive and cannot be removed. Besides, gene silencing methods provide a more complete view on the development of diseases since diseases are generally associated with genes that have a reduced expression.