https://docs.magento.com/m2/ce/user_guide/design/page-layout-standard.html

Standard Page Layouts

1 Column

The “1 Column” layout can be used to create a dramatic home page with a large image or focal point. It’s also a good choice for a landing page, or any other page that has a combination of text, images, and video.

2 Columns with Left Bar

The “2 Columns with Left Bar” layout is often used for pages with navigation on the left, such as a catalog or search results pages with layered navigation. It is also an excellent choice for home pages that need additional navigation or blocks of supporting content on the left.

2 Columns with Right Bar

With a “2 Columns with Right Bar” layout, the main content area is large enough for an eye-catching image or banner. This layout is also often used for Product pages with blocks of supporting content on the right.

3 Columns

The “3 Column” layout has a center column that is wide enough for the main text of the page, with room on each side for additional navigation and blocks of supporting content.

Empty

The “Empty” layout can be used to define custom page layouts. To learn more, see the Magento Designer’s Guide.