Why is dehydrohalogenation reaction in haloalkane termed as `beta-elimination ?

Explanation

When a halogen is heated with conc. alcoholic solution of KOH, a molecule of hydrogen halide is eliminated and an alkene is formed. The hydrogen of alkyl halide which is eliminated comes from a `beta`- carbon and halogen from a- carbon due to the elimination of H-atom from B-carbon this reaction is called ß- elimination reaction e.g.