Containers are used to pad the content inside of them,and there are two container classes available,The.container class provides a responsive fixed width container,The .container-fluid class provides a full width container, spanning the entire width of the viewport,By default, containers have 15px left and right padding, with no top or bottom padding. Therefore, we often use spacing utilities, such as extra padding and margins to make them look even better. For example, .pt-3 means "add a top padding of 16px":
