Windows Vista was a shock to many Windows users, as its hardware requirements represented a steep upgrade over those required to run Windows XP: most 32-bit versions required a 1GHz processor, 1GB RAM, DirectX 9 graphics, and 40 GB of mass storage with 15GB free. But those 2006-era requirements looked much less steep once Windows 7 rolled out in 2009: it required almost the same system specs, but now 16GB of available disk space instead of 15. Windows 8 again stuck with the same specs and, at its release, so did Windows 10.
But the Windows 10 Anniversary Update (referred to in documentation as version 1607, so it ought to ship in July) changes that, with the first meaningful change in the Windows system requirements in almost a decade. The RAM requirement is going up, with 2GB the new floor for 32-bit installations. This happens to bring the system in line with the 64-bit requirements, which has called for 2GB since Windows 7.