Factless Fact Tables

Fact tables which contain only foreign keys to join dimensional tables but not any measures for analysis to feed the user's query. It is used to define many to many relationship between two dimensional tables.It works as an interface table to correlate the data residing in 2 or more than 2 dimensional tables. Suppose our query requires data fetching from both table then fact less dimensional table is required which relates 2 dimensional tables. However we do not require any data in fact table to feed the query. But it contains only foreign keys and not any fact or event.
So many to many relationship can be defined between 2 dimensional tables using fact less fact tables।