Bootstrap provides us with different classes that can be used with different tags, such as <button>, <a>, <input>, and <label> to apply custom button styles. Bootstrap also provides classes that can be used for changing the state and size of buttons, also, it provides classes for applying toggle, checkbox and radio buttons like effects.
Solid Buttons: Bootstrap provides us a series of classes that corresponds to different solid button styles. These classes are listed below:
btn-primary btn-secondary btn-success
btn-danger btn-warning btn-info
btn-light btn-dark btn-link
Note: We must use additional btn class with the classes mentioned above and that follows.