When you create or restore your wallet on Eidoo, the app requires you to choose a password which has to be composed of at least 8 characters. Eidoo also allows the use of biometrics (as fingerprint or face unlock/ID) to make the login procedure faster and safer.
The password and the fingerprint serve the purpose of ensuring that it is actually you that is accessing the application from your device. However, it only works locally. If someone somehow came to know your seed, they could still spend the funds stored in the corresponding wallet by accessing from their devices, so remember to never share your seed with anyone, ever!
Read more about the seed and how to keep it safe and avoid scams, click here.