Calendar table is frequently used to perform Time Intelligence functions and in many scenario we need calendar table. If you don’t have any date table in your data model, you can easily create date table using some DAX functions.
Evaluates an expression against a list of values and returns one of multiple possible result expressions. It’s comes under Logical Dax function category.
As it’s name suggests, Returns all the rows in a table, or all the values in a column. ALL function removes the applied filters from the filter context. Its comes under Filter function DAX category.