Intellisense is basically auto-completion when you are typing.
This displays a short description of member, function, arguments etc next to the cursor and is a convenient way to access functions, parameters, enumerations etc.
Using intellisense speeds up development by reducing keyboard input.
Auto List Members
This displays a tooltip containing a list of methods and properties.
SS - icon methods
SS - icon properties
This looks like tooltips that are relevant to the current line and current scope.
The user can then select one from the drop-down using the arrow keys and then hitting the completion character (Tab) or (Enter).
You can show pop-up manually (Ctrl + J) or (Ctrl + Space)
Auto Quick Info
Displays information about functions and their corresponding arguments.
SS - Call MsgBox()
There is no intellisense with the following code
This is because the Sheets collection can contain two different types of objects
This is because ??