Original remains are the unchanged fossilized remains of animals and plants. They can include things like animals trapped in ice and insects fossilized in a resin, such as amber.
Fossils come in a number of different varieties. Besides original remains, there are also replaced remains, where part or all of a plant and animal has been replaced by minerals over time. Molds and casts are other types of fossils. This happens when molds of all or part of a plant or animal is created from mud, sediment or minerals. Trace fossils are those fossils that simply contain evidence of an organism's existence.