The difference between cluster sampling and stratified sampling would be:

There is no difference. It is two names for the same type of sampling.

Each divides the population into groups. Cluster sampling uses some in each group while stratified uses all in selected groups.

Each divides the population into groups. Stratified sampling uses some in each group while cluster uses all in selected groups.

Cluster divides the population into groups and uses all in selected group while stratified uses some only in selected groups.