Fact Table contains the measurements or metrics or facts of business process. If your business process is "Sales" , then a measurement of this business process such as "monthly sales number" is captured in the Fact table. Fact table also contains the foriegn keys for the dimension tables.

Facts are organized in a table is called Fact table.

A Fact is a numeric values or a Business measure.

Every numeric is not a fact. a numeric which occupied a key performance indicator is called Facts

A Fact table contains a Facts at lower granularity level