What this means is that users will be able to swap out components like battery, camera modules, flash modules, storage, and so on. Presumably third-party manufacturers would also be able to create these modules which ultimately would result in a highly-customized smartphone.
The good news is that things appear to be progressing fairly smoothly as Google has recently announced that they will be holding their inaugural Ara Developers’ Conference from the 15-16th of April. The conference will focus on the Ara Developers’ Module Kit which basically gives developers the ability to create components that will be compatible with the device.
Google will also be planning two more Ara Developers’ Conferences later in the year, although those dates have not been mentioned yet. Project Ara is one of the projects worked on by the Google Advanced Technology and Products department which they retained when they sold Motorola to Lenovo.