Bootstrap 4
Bootstrap 4 Position
Quickly configuring the position of an elements are .position-static, .position-relative, .position-absolute, .position-fixed, .position-sticky.
<div class="position-static">...</div>
<div class="position-relative">...</div>
<div class="position-absolute">...</div>
<div class="position-fixed">...</div>
<div class="position-sticky">...</div>
Fixed top

Position an element at the top of the viewport, from edge to edge. Be sure you understand the ramifications of fixed position in your project; you may need to add aditional CSS.

<div class="fixed-top">...</div>
Fixed bottom

Position an element at the bottom of the viewport, from edge to edge. Be sure you understand the ramifications of fixed position in your project; you may need to add aditional CSS.

<div class="fixed-bottom">...</div>
Sticky top

Position an element at the top of the viewport, from edge to edge, but only after you scroll past it. The .sticky-top utility uses CSS’s position: sticky, which isn’t fully supported in all browsers.

Microsoft Edge and IE11 will render position: sticky as position: relative.

<div class="sticky-top">...</div>