sm button in bootstrap code example

Example 1: large button in bootstrap

<!-- Large buttons -->
<button type="button" class="btn btn-primary btn-lg">Large button</button>

<!-- Medium Buttons -->
<button type="button" class="btn btn-primary">Large button</button>

<!-- Small Buttons -->
<button type="button" class="btn btn-primary btn-sm">Large button</button>

<!-- Block Buttons -->
<button type="button" class="btn btn-primary btn-lg btn-block">Block level button</button>

Example 2: bootstarp btn colors

<button type="button" class="btn btn-primary">Blue</button>
<button type="button" class="btn btn-secondary">Grey</button>
<button type="button" class="btn btn-success">Green</button>
<button type="button" class="btn btn-danger">Red</button>
<button type="button" class="btn btn-warning">Yellow</button>
<button type="button" class="btn btn-info">Ligth blue</button>
<button type="button" class="btn btn-light">White</button>
<button type="button" class="btn btn-dark">Black</button>

<button type="button" class="btn btn-link">White with blue text</button>

Example 3: bootstrap Buttons

Bootstrap includes several predefined button styles, each serving its own
semantic purpose, with a few extras thrown in for more control.
Using color to add meaning only provides a visual indication, which will
not be conveyed to users of assistive technologies – such as screen readers. 
Ensure that information denoted by the color is either obvious from the 
content itself (e.g. the visible text), or is included through alternative
means, such as additional text hidden with the .sr-only class.

<button type="button" class="btn btn-primary">Primary</button>
<button type="button" class="btn btn-secondary">Secondary</button>
<button type="button" class="btn btn-success">Success</button>
<button type="button" class="btn btn-danger">Danger</button>
<button type="button" class="btn btn-warning">Warning</button>
<button type="button" class="btn btn-info">Info</button>
<button type="button" class="btn btn-light">Light</button>
<button type="button" class="btn btn-dark">Dark</button>

<button type="button" class="btn btn-link">Link</button>

Example 4: bootstrap disabled button

<button type="button" class="btn btn-lg btn-primary" disabled>Primary button</button>
<button type="button" class="btn btn-secondary btn-lg" disabled>Button</button>