Where do satellites go once they stop functioning?

Could you please elaborate on the fate of satellites that have ceased to operate? What happens to these spacecrafts once they have reached the end of their lifespan? Do they simply float aimlessly in space, or do they follow a specific path? Additionally, are there any measures in place to ensure that these defunct satellites do not pose a threat to other functioning spacecrafts or Earth's environment? It would be interesting to know the procedures and considerations involved in the disposal or management of these non-operational satellites.