adjective is a word that modifies a noun or pronoun by describing, identifying, or quantifying words. In the case of traditional, it is used to describe something by referring to the idea that it is part of a culture or custom that has been practiced for a long time.
The professor discussed traditional teaching methods.
He wore his traditional wedding tuxedo.
when describing something as traditional, it is often assumed that it is viewed positively although this isn't always the case. For example, you could use it in a sentence such as, 'The traditional view of marriage favors male dominance.'