The similarities between fingernails and toenails are many because of the functionality, properties and stability related aspects. Without both, we would not be able to function properly and would face a number of problems performing everyday tasks. Having said that, this does not mean that they are entirely the same in each and every way; they are also different in their own special ways.
While both fingernails and toenails may have the same functionality of protecting the fingertips as much as they possibly can, but a major difference between them is that the latter is much harder than the former. There is a much higher chance of toenails being ingrown as well as compared to fingernails. The ingrowing can be extremely painful as the nail, which is supposed to grow outward, begins to grow towards the skin it is meant to protect. Fingernails are also an indication of general health; the colour marks and spots on your nails can mean the difference between a healthy human being and something being internally wrong.
The speed of growth of toenails and fingernails is very different as well. Toenail grows at a much slower pace as compared to a fingernail.