A container is an element that holds all your site contents. You can access the Container Layout option via Admin Dashboard > Appearance > Customize > General Options > Layouts > Container.

The following are the settings that you can use to manage your site container layout.
Container Width – You can set the site container width for different devices via this option.
Layout – Choose the site layout here.
Fullwidth Centered Max-width – This setting sets the container width for a full-width centered layout.
Container Vertical Spacing – Set the vertical spacing value for the site container via this setting.
Container Stretched Padding – Set the padding value for the stretched container.