Meaning of the word "main door" in English

What does "main door" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

main door

US /meɪn dɔr/
UK /meɪn dɔː/

Noun

the principal entrance to a building

Example:
Please use the main door when entering the building.
The delivery driver left the package by the main door.