Project Ara is Google’s effort to develop a modular smartphone that can be built as per customer requirements based on the open hardware protocol. As per Google, the attempt is to build a next generation smartphone with cheaper components that could connect the next 5 billion people. The project allows users to build their own smartphones with custom parts that will be made available from major stores and carriers according to the users own aesthetic and functional preferences.
What this means is that the user only has to buy the structural framework called the “endo” (comes from endoskeleton) and then either develop custom parts as per their requirements or buy components that could be fit into the endo to create a fully functional smartphone.
Therefore next time when users have to upgrade their smartphones, they do not have to buy a completely new one. Instead they can just swap components on the fly to build a more powerful and upgraded device, just like Lego.