Forgive the vague question title.

I've been programming mobile apps for 3 years now, and I've got a little too far from the web services and server side code then I probably should have.

Anyway, I'm doing a personal project now and I want to create an web API for it. One of my requirements is to check for updates from my app, so I would send a timestamp to the API.

I've used many APIs that my clients prepared for me and only now am I appreciating their work !

What is the term or technique used to create an API backed by a database which tracks changes via dates/timestamps, basically an effective way for me to query changes occurring since a timestamp.

Simply put, I want that my app can call my API in order to sync new data and changed data from the server, to the app. The app would only have a timestamp of the last time it synced with the server.

Would I have a log table for each data table in my database which adds a record for each change? Then I could query all changes with a timestamp superior to the one passed to the API.

Can anyone point me in the right direction on this?