As far as I understand, outdoor roped climbing falls into three categories; top roping, sport and traditional (trad).
Top roping involves a climber being on the end of a rope which has been set up from the top of the climb. The partner belays (controls) the rope as the climber ascends. There is always the security of being safely attached from above. Top roping is mainly for beginners, but can sometimes be used for trying out routes graded above the ability of the climber as a prerequisite for attempting the route by leading it. However, if the climber is logging climbs with UK Climber, it must be recorded as a route climbed after top rope inspection, rather than as O/S (on sight).
With sport climbing, the lead climber is belayed from below by his second. Routes are already marked out with bolts in the rock to which climbers can attach their safety gear during the ascent. The bolts and ropes are not intended to aid the ascent, purely as a safety measure; to ensure that any fall is only to a short rope length below the last bolt. On reaching the top of the route, the lead climber will set up an anchor and then belay a second up to the top. The second will detach all gear from the bolts as he climbs. Most sport routes are single pitch.
With trad, the placing of protection is down to the climber, who must find suitable cracks in the rock in which he can place gear (nuts, hexes, cams etc - leading to some interesting calls about the various placements of nuts.) The lead climber places this protection as he climbs and the second collects it during his ascent. Trad climbing is generally more risky than sport. The climbing at Stanage is trad.
Since he went to university, Mark has been building up his climbing rack. It's not quite complete, but it's pretty close. Personally, I look at the amount of stuff dangling from his harness and wonder how he ever gets off the ground.
But get off the ground he does. This is Mark leading up Flying Buttress Gully. Ben is below on belay. It was their first climb of the day and made a good warm up.
They followed it by climbing next door Flying Buttress; Ben seconding below...
...and winding up towards his first ever outdoor lead.