An animation lets an element gradually change from one style to another. You can change as many CSS properties you want, as many times as you want. To use CSS animation, you must first specify some keyframes for the animation.
The @keyframes Rule

When you specify CSS styles inside the @keyframes rule, the animation will gradually change from the current style to the new style at certain times.

To get an animation to work, you must bind the animation to an element.

The following example binds the “example” animation to the

Flexbox is a one-dimensional layout method for arranging items in rows or columns. Items flex (expand) to fill additional space or shrink to fit into smaller spaces. This article explains all the fundamentals.
CSS Flexbox, short for Flexible Box Layout, offers a streamlined way to design adaptable and visually appealing layouts. It works primarily in one dimension (row or column) to intelligently distribute space among elements within a container, resulting in clean alignment and responsive designs suitable for various screen sizes. Flexbox is perfect for crafting both smaller components and overall webpage structures.

Features of flexbox:
High flexibility
Arrangement & alignment of items
Proper spacing
Order & sequencing of items
Bootstrap 4 is built on top of the flex layout
Before the Flexbox Model:
Block: Sections in web pages
Inline: Text
Table: Two-dimensional table data
Positioned: Explicit position of an element