What is the difference between a selectable marker and a reporter gene?

Selectable makers and reporter genes are two types of genes used to analyze transformants. A selectable marker is used to distinguish between cells that have been transformed and cells that have been transfected with a vector containing the marker gene. Whereas, a reporter gene is used to tag another gene or a promoter and measure the level of the expression of the transformed gene. The major difference between the reporter gene and the selectable marker gene is the difference in the type of screening.