The practical aspects of something involve real situations and events, rather than just ideas and theories.

You describe people as practical when they make sensible decisions and deal effectively with problems.

Practical ideas and methods are likely to be effective or successful in a real situation.

You can describe clothes and things in your house as practical when they are suitable for a particular purpose rather than just being fashionable or attractive.

A practical is an examination or a lesson in which you make things or do experiments rather than simply writing answers to questions.