A layout is a 2D working environment for creating drawing sheets.
The area within a layout is called paper space, where you can add a title block, display scaled views of model space within layout viewports, and create tables, schedules, notes, and dimensions for your drawing.
You can access one or more layouts from the tabs located at the bottom-left corner of the drawing area to the right of the Model tab. You can use multiple layout tabs to display details of the various components of your model at several scales and on different sheet sizes.
There are several ways in which you can add new layouts or copy existing layouts.
Use the LAYOUT command
Right-click a layout tab
Step through the Create Layout wizard
Each layout stores its own page setup which controls the appearance and format for displaying and printing each layout. For example, you would use the page setup to specify the sheet size and orientation. The Page Setup Manager is accessible from the PAGESETUP command, the Application menu, and the ribbon.