App store asking for someone else's password in order to update apps

Hello, I have been having a lot of trouble lately. When I try to update my applications, it asks me for a password from an apple ID that is not mine. I do not know the password, and therefore cannot update my applications. I am very confused because I am signed into my own account in both the App Store and in settings, but it still keeps asking for someone else's password. I have no idea what to do. Any help would be much appreciated.