How to add plugin options in wp editor page

Question

I am getting back at wordpress development after few years. I'm not sure what are they called and therefore I can't find right information about them :S

I want to add few options on wp editor page so user can use those settings to customize few settings.

I want to know what they are called and if possible link to dev doc for it.

A: Yoast plugin have options settings below the content editor
B: I see some plugin can add its own section menu on top right
C: Some plugin can also add options menu on right sidebar below.

Can any one please provide some information about them what they are called and if possible some link to tutorials will be great.

Answer 1

These are post meta. Here are some information to get you started.

• Custom Meta Boxes
• Rendering Post Metadata
• Add Meta Box