Limestone is a sedimentary rock whereas gravel can be made up of unconsolidated rock fragment.
Limestone is often more uniform in colouring, usually coming in white, buff or grey.
Gravel is made up of many colours, with common options being brown, white or a mixture of shades.
The shape of quarried limestone and gravel is also different. Limestone is jagged and sharp, while gravel is often round and smooth.
While aesthetics is important when selecting between limestone and gravel for applications like a driveway or footbath, both products do look very tidy and decorative when placed, maintenance also needs to be considered. Limestone is a lower maintenance product and once placed, due to the angular nature of the crushed material, locks into place and forms a more stable and zero maintenance driveway or footpath. Gravel on the other hand is a more rounded particle and therefore shifts about under the weight of a foot or vehicle. In order for gravel to remain looking decorative and tidy, it requires regularly raking into position.
For drainage and pipe bedding purposes, most contractors prefer to use limestone as it locks into place and is, generally speaking, cheaper.