Why store tables in another table?

Question

I have seen that people often use a separate table to store relationships between tables.

For example, the Company_companys table has two columns: nodeid, which is the company identifier, and linkid, which is the company of another company.

Why do people do this when the same thing can be done with an extra column in the company table? Is it for performance reasons? or is there some other reason?

EDIT: Thanks to everyone for the answers and examples. Now I understand that in order to reach the first normal form, when many, many relationships are required, a separate table is needed to store several links. When I reflected on the above question, I almost forgot the concept of many, many relationships, so I thought about it from one to many relationships :)

Answer 1

This is probably due to the fact that it is a MANY TO MANY relationship . With the approach you are talking about, you have only ONE TO MANY .

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Answer 2

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Answer 3

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