Thankfully, there's now a way to bake ADB and Fastboot into the Windows command prompt itself, which lets you immediately run ADB upon opening the command prompt. That way, the mod files, plus the adb.exe and fastboot.exe files, would be in the same place, giving the Windows command prompt everything it needs. So until now, the easiest way to install mods with ADB or Fastboot was to move necessary files into the platform-tools folder, then open a command window in the same folder. But if you're sending any files or mods over to your Android device, the Windows command prompt also needs those to be in the same folder, unless you're willing to type out the full file location. The platform-tools folder is significant because it houses a pair of files ( adb.exe and fastboot.exe) that the Windows command prompt needs to reference before it can send any ADB or Fastboot commands. The problems often stem from having to hunt for various files - usually IMG or ZIP files that you need to mod your Android phone - and then move them to your platform-tools folder, which, depending on how you installed ADB in the first place, could be anywhere.

Unless you're experienced using the Linux terminal, running ADB and Fastboot commands can get confusing very fast.

Adb and fastboot platform tools