I know ids are used extensively in mysql tables to identify records but what could node_id mean? I inherited a custom php framework that makes use of this term constantly and also has db column names called node_id. What could this be used to mean?
node_id
is just a column name. Without any context it's pretty impossible to know what it means. You'll usually just have to dig through the ORM or however the database is implemented to figure out what it's doing, if you don't have proper software specs or other useful notes anywhere.
It is just a name of the coulmn, without any special magic meaning