.XLS .XLSX .XLSM (Macro-enabled workbook) .XLSB (Binary format) .CSV (Comma Separated Values)
In 2 ways we can pass arguments to VBA
Code Module: Default module to write procedures.
User form: Helps to develop GUI (Graphical User Interface) applications.
Class Module: Allows to create new objects.
The Collection object contains a set of related groups of items as a single object.
Collections and Arrays are used to group variables. In Arrays, before using to start adding elements we normally set the size. But in Collection, we will not set the size, because we don’t know the number of elements in advance.

new sample description here