When comparing the two terms, one could say that recruiting is a broad term that refer to the practise of attracting, screening, and interviewing potential candidates. On the other hand, sourcing is a small subsection of the prior. “Sourcing” is pretty similar to “scouting”. You are essentially seeking out talent in the market by proactively looking to their work and reaching out for a potential interview. Sourcing as a practise is more popular with tech companies where good talent is hard to find. As such, most recruiting conferences in 2020 have at least some seminar or keynote about the improvement of such practices.