Pump tracks are becoming increasingly common worldwide, but if your town doesn't have one yet, a BMX track or flow track are good substitutes.  

You can use any bike to learn to pump. A dirt jumper is the most efficient, but most trail bikes can be set up to improve ride quality. The burlier the bike (e.g. enduro e-bike), the more effort is needed to Pump full laps. 

If you grew up riding BMX, you'll likely have good Pumping technique already, as it's a key part of the sport. However, self-taught mountain bikers or YouTube learners have most likely developed Sub-Optimal technique.

The ability to cut laps at the track is not necessarily an indicator of good technique – in fact, many riders are Pumping backward, which limits top speed, bump absorption, and cornering ability. You can't fake it until you make it, as you'll reach an inevitable plateau.

The pump track is the perfect mountain bikers' gym, allowing riders to hone their pumping and cornering in a controlled environment. Pumping the trail allows you to create more speed without pedaling while absorbing upslopes to keep the bike grounded. Pumping corners means more speed, grip, and flow. It all adds up to a higher trail speed and smoother ride.

The key thing all top riders share is that they are skilled at Pumping. If you marvel at how some riders are just so damn fast, pumping is the difference.