“Side hustle” has become a common term these days. It’s something that you do on the side of your main job that brings in extra cash, or may generate income later.
To me, a side hustle is said when you’re doing something that’s an alternative to your main job or current pursuit. That’s why I like the term “Dual track strategy” more (Not as catchy I know, but stay with me).
For me, a dual track strategy is running two or more strategies whose benefits build on each other (like 1 + 1 = 3). So you may be trying to maximise your income in your main job, while expanding your network in other ways, or studying, or volunteering to earn particular experience.
Either way, the two terms have the same essence and are a great approach to take in life. There are fantastic benefits to gain when you explore things outside of your main pursuit (even if you’re passionate about it).