star schema is a logical structure that can be arranged with fact and dimension tables

in a star formation.it looks like a star with fact table at the core of the star and the dimension tables along the spikes of the star.the dimension model is therefore called a STAR SCHEMA.

SNOWFLAKING is a method of normalizing the dimension tables in a star schema.

Star Schema: can have less number of joins.

Snow flake: can have more number of joins.

Star Schema : has data redundancy, so the query performace is good.

Snow flake: is normalized, so does not has data redundancey. can have perfomance issues.