What components are needed to connect to a
firebird database in
Delphi to display these tables in a DBGrid and how should they be related by properties?
In my projects I used Zeos components to connect to FireBird. They are third-party but free.
Installation instructions are here.
Some of the steps of connecting and linking can be viewed here , it describes the connection to mysql, but the settings are very close.
There is also a paid version of UniDac.
If you do not use third-party components, then
IBDataBase database itself and parameters
There, in the property inspector, you will understand what to connect and how.