How does this Zwift work, do you pay a subscription?
yeah, it was £8 p/month (still is for existing subs) or £12 p/month now for new subs
your trainer connects to your pc/laptop by using your phone as a bridge
if you have a dumb trainer you need to buy a speed and cadence system for it to 'guesstimate' your power (poor people option)
if you have a smart trainer it uses the figures from that
if you have a powermeter it uses the figures from that
if you have a super duper smart trainer it will vary the resistance when going up hills, and some of them even have motor assist for extra realism on the downhills (if you have a super super duper duper smart trainer)