According to the story, a united humanity in the generations following the Great Flood, speaking a single language and migrating eastward, comes to the land of Shinar (שִׁנְעָר).
There they agree to build a city and a tower tall enough to reach heaven. God, observing their city and tower, confounds their speech so that they can no longer understand each other, and scatters them around the World.
The story of the Tower of Babel explains the origins of the multiplicity of languages. God was concerned that humans had blasphemed by building the tower to avoid a second flood so God brought into existence multiple languages. Thus, Humans were divided into linguistic groups, unable to understand one another.
Therefore is the name of it called Babel; because the Lord did there confound the language of all the earth: and from thence did the Lord scatter them abroad upon the face of all the earth. – Genesis 11:9