There is also a difference in the timescale used to explain the layers.
Determining the relative age of a rock layer is based on the assumption that you know the ages of the rocks surrounding it.
Relative ages are assigned to rocks based on the idea that rock layers lower in the strata were deposited before rock layers that are higher.
Creationists do not necessarily disagree with this concept, but it can only be applied to layers that are found in one location and/or can be determined to have been deposited in a continuous layer over a very wide area.
Recent research by a team of creation scientists known as the RATE (arth) group has demonstrated the unreliability of radiometric dating techniques.