Java – What is the difference between ANDROID_HOME and ANDROID_SDK_HOME

I have 2 directories that look the same,

ANDROID_HOME=C:\Android\sdk

ANDROID_SDK_HOME=C:\Users[user]\AppData\Local\Android\Sdk

What’s the difference?
Can I set it in a directory?

Based on documentation :

ANDROID_HOME

ANDROID_HOME, point to the SDK installation directory. This has been deprecated, please use ANDROID_SDK_ROOT instead.

If you continue to use it, the following rules apply:

• If ANDROID_HOME is defined and contains a valid SDK installation, its value is used instead of the value in ANDROID_SDK_ROOT.
• If ANDROID_HOME is not defined, the value in ANDROID_SDK_ROOT is used.
• If ANDROID_HOME is defined but does not exist or does not contain a valid SDK installation, the value in ANDROID_SDK_ROOT is used instead.

ANDROID_SDK_HOME

The root directory of the user-specific directory where all configuration and AVD content is stored

can I set it in one dir?

Ideally you shouldn’t do this because they serve different purposes.