1. Add the HTML5 doctype
2. Bootstrap 3 is mobile-first
3. HTML meta charset Attribute
4. Containers
Bootstrap Containers:-
Bootstrap Containers are used for wrap site contents.
There are two types container classes.
1. The .container class provides a responsive fixed width container
2. The .container-fluid class provides a full width container
Note: Containers are not nestable (you cannot put a container inside another container).