Same number of syllables in each line. It's wonderful how I jog on four honed-down ivory toes my massive buttocks slipping like oiled parts with each light step. Seven syllables each time. Not as easy as Levine makes it seem. Okay, I'll stop.
Meter is all about rhythm.
All of this is covered in more depth in Appendix A of our textbook Strong Measures . I hope this gives you a good start, though.