CSS layout
CSS page layout techniques allow us to take elements contained in a web page and control where they are positioned relative to their default position in normal layout flow, the other elements around them, their parent container, or the main viewport/window.

Each technique has its uses, advantages, and disadvantages, and no technique is designed to be used in isolation. By understanding what each method is designed for you will be in a good place to understand which is the best layout tool for each task. and these techniques are :
- Normal flow
- The display property
- Flexbox
- Grid
- Floats
- Positioning
- Table layout
- Multiple-column layout

This Link will led you to more calrification for the CSS layout.