The Keystore is an encrypted version of your Private key in JSON format. Keystore is like Private key except that it is protected by a password of your choosing. It is safer than the Private key because you need a password to access it. Here are some tips to keep it safe:
1. When you are creating your password make sure it is a strong password and it is unique to the imToken APP. This should be a new password that has a mixture of punctuations, letters, and numbers.
2. Make sure to remember your Keystore. If you forget the password, there is no way for the password to be recovered and you can no longer use the Keystore.
3. Store your Keystore and password separately. If someone gets ahold of only your Keystore, the wallet cannot be cracked quickly without knowing the password.
4. Do not use mailboxes or other online software to transmit Keystore or password.