.btn btn-defaultclass used to give transparent colour to button.
.btn btn-primaryclass is used to give blueish colour to button.
.btn btn-successis used to give the greenish colour to button.
.btn btn-infoclass is used to give the skyblue colour to button.
.btn btn-warningclass is used to give the yellow colour to the button.
.btn btn-dangerclass is used to give red colour to the button.
.dropdown-menu under ul component is used to make the dropdown list and
.dropdown-toggle is used to make the dropdown toggling on click of button.Class
.caretin span is used to make the arrow sign in dropdown.
.btn-groupclass is used to make a group of buttons.
.btn-group-lgcan be used to make button large.
.btn-group-justifiedused to cover entire span of screen.
.btn-group-verticalused to make buttons vertical.
.btn-lgused to make big size button.
.btn-mdused to make medium size button.
.btn-smused to make small size button.
.btn-xsused to make extra small size button.
.btn-blockused to make block size buttons.
.disabled classes are used to active and disabled states of buttons.
Whatever written in
data-loading-text attribute will show as button text at the time of loading and the time is also set to do the button again active.
Example shows the toggeling button which changes its state on every click.