What do atomic values represents?
I have read the definition of 1NF which is, "If each attribute of relation is atomic". Please tell me what is Atomic.?
Atomic value represents to Codd's original notion from 1969 that each attribute in each tuple within a relation should consist of a single value and not allow multivalued structures of the kind supported in databases like the CODASYL model.
In modern SQL DBMSs atomicity isn't really an issue. SQL tables do not allow multivalued columns and values are always "atomic".