Good to see the Appium 1.8.1 release, but I'm confused which one should I download?

Good to see the Appium 1.8.1 release, but I’m confused which one should I download? Which one is preferable for windows 64 bit?
1st one for Windows 32 bit and 2nd one for 64 bit, if I’m right, what about 3rd and 4th one?

3rd one is blockmap file.
Refer here for more details :https://github.com/electron-userland/electron-builder/issues/2851

4th one is Appium installer
This is what is called an NSIS-Web installer. What it does is it checks your environment (Windows OS version, 32 v. 64 bit, etc…) and then downloads the appropriate installer.

Refer here for more details: Windows Appium Desktop woes