Can you explain start schema in Qlikview?

Star Schema:

A start schema model is a type of data model in which multiple dimensions are linked to a single fact table. Of course, in bigger models there can be multiple facts tables linked to multiple dimensions and other fact tables. The usefulness of this model lies in performing fast queries with minimal joins among various tables. The fact table contains data, which are measures and have numeric values. Calculations are applied on the fields in the fact table. The unique keys of the dimension tables are used in linking it to the fat table, which also has a key usually with the same field name. Therefore, the Fact table contains the keys from the entire dimension table and forms a concatenated primary key used in various queries.

Difference between star schema and snow flake schema?

Star Schema: 

In a star schema, the fact table will be at center and in connected to dimensional tables. The tables are completely in De normalized Structure. SQL queries performance in good as there are less number of joins involved. Data redundancy is high and occupies more disk spaces. 

Snowflake Schema:

 is an extension of star schema where the dimension tables are further connected to one or more dimensions. The tables are partially de normalized in structure. The performance of SQL queries is little bit less compared to star schema as more no. of joins are involved. Data redundancy is low and occupies less disk space compared to star schema.