1. Atomic Values: Every column of a table should contain only atomic values, which means that a value cannot be divided further
  2. No Repeating Groups: A table should not contain repeating columns or groups of data
ID   Name   Courses
1    A      c1, c2
2    E      c3
3    M      C2, c3

This table is not in 1NF because the “Courses” column contains multi-valued attributes, which are not atomic.

ID   Name   Course
1    A       c1
1    A       c2
2    E       c3
3    M       c2
3    M       c3