Resilient flooring, quite simply, is flooring that flexes -- or "bounces" -- as you walk on it. Wood, being flexible and shock absorbent, is an obvious candidate as a resilient flooring material. Linoleum, vinyl or rubber tiles and vinyl sheet flooring are, likewise, resilient. Cork flooring offers the most bounce when walked on.
Non-resilient flooring materials do not flex or spring when walked on. The most non-resilient surface would be a concrete slab. Even when installed on a wood subfloor, ceramic tile offers minimal or no resilience, so it's considered non-resilient flooring. Likewise, marble and granite tiles are non-resilient.
The subfloor affects whether a flooring material is resilient or not. If you install vinyl tiles, for instance, on a concrete slab, you'll have a hard, non-resilient floor. If you install them on a wood subfloor, however, you'll have a resilient floor. If you have a concrete slab and install wood or cork floors, on the the other hand, you'll have resilient floors.
Resilient flooring is often installed where there is a lot of standing and walking because they soften the blow of the feet on the floor. Resilient flooring is good for kitchens and professional work spaces where workers stand all day. Professional chefs, bank teller and cashiers often find resilient flooring a back-saving thing. Non-resilient flooring is desired where durability and water-resistance are required. You'll find these materials in bathrooms and high-traffic public spaces, such as shopping malls.
If you have a ceramic or concrete kitchen floor and find that it's hard on your back, you can do a few things to soften the floor's impact. A deep pile area or throw rug softens the impact and allows for comfortable standing for longer periods of time. You can get get the rubber pads at home centers that bank tellers and cashiers often use on hard floors. One placed in front of the sink or your favorite work area can greatly increase your comfort level.