Below we are summarizing the Bootstrap provided the important classes to use button groups.
This class .btn-group used for basic button group. Wrap the series of button using .btn class in .btn-group.
This class helps to combine sets of buttons (<div class="btn-group">) into a toolbar (<div class="btn-toolbar">) style for more complex components.
.btn-group-lg, .btn-group-sm, .btn-group-xs
These classes can be functional to button group instead of resizing every button.
This class use for change appearance vertically stacked rather than horizontally a set of buttons.
Basic Button Group
Following examples demonstrates the use of class .btn-group discussed in the above:
To use justified button groups with <button> elements, you must wrap each button in a button group. Most browsers don’t properly apply our CSS for justification to <button> elements, but since we support button dropdowns, we can workaround that.