Once you have the InstallESD.dmg or the Combo Update DMG, the usage depends on your goal:
Scenario A: Updating an Existing Mac
Scenario B: Creating a Bootable USB Drive (Clean Install) If you have the full installer extracted from the DMG: mac os x yosemite 1010 5 download dmg link
Apple does not provide a direct DMG download for Yosemite on its public website. Instead, the official, supported method is to retrieve the installer through the Mac App Store (or Apple’s “Purchased” page) using an Apple ID that has previously “purchased” the OS. Below are the steps to acquire a legitimate copy: Once you have the InstallESD
Before Yosemite, OS X was distinctly separate from iOS in look and feel. Yosemite introduced "Continuity," blurring the lines between the Mac and the iPhone/iPad. It introduced the "Dark Mode" for the first time and revamped system fonts (introducing Helvetica Neue to the Mac). Scenario B: Creating a Bootable USB Drive (Clean
However, Yosemite was also controversial. Early versions were criticized for Wi-Fi connectivity issues and sluggish performance on older machines. This is why the 10.10.5 update is so critical. As the final patch released before the launch of OS X El Capitan (10.11), 10.10.5 is widely considered the only version of Yosemite stable enough for daily use. It fixed the infamous "Rootpipe" vulnerability and stabilized the Handoff/Continuity features.