What is the difference between KMS and Secrets Manager? They seem to be very similar.
Julio provided a great answer. A simple way to look at it is that KMS is all about generating new keys while Secrets Manager is all about storing/retrieving existing passwords/keys.
KMS is a service to manage cryptographic keys to encrypt your data at rest but secret manager is a service where you can store your passwords in variables and use the variables in the application instead of hard coding a password. Your application will query the password every time it is needed and Secret Manager will rotate your password automatically. Of course there is more to both services but this is the basic difference. You can check the following links to learn further: