Diferences Between Bootstrap 3 and 4
From Logic Wiki
Bootstrap 4 Changes:
- Built on top of Flex CSS
- Refactored most components
- Removed panels, thumbnails, and wells
- Added a new component : cards
- Uses rems instead of px (all font sizes are relative to root element)
- New grid size/tier
- LESS to SASS
- Dropped Glyphicons
- Tons of new utility classes
