Overlay / modal / alert / dialog / lightbox / popup
Toaster / snackbar — Notify the user with a modeless temporary little popup
Let the user know that something is loading
Fixed headers / scroll-up headers / sticky elements
Let the user enter data
Date picker / time picker / datetime picker / date range picker
Masked inputs, specialized inputs; email / telephone number / credit card / etc.
Autosuggest / autocomplete / typeahead
Layout the overall / main view
Report changes about a DOM element
Turn user input into actions
Display large lists
Filter large lists
Framework to layout your app in a specific way