The system can be configured to send alerts if a door/window is opened/closed, or left open for a programmable period of time. If you're out-of-town you can setup the door opened notification to tell you instantly if a door is opened (security use-case). If you have children in your home you can use the other alert type to inform you if a door is left open (such as in the evening when a door most likely should not be left opened). 

Here is a video showing how to set these up via the App: https://youtu.be/_AkDSc0lgGs

Here is a video showing how to set these up via the Website: https://youtu.be/rrtqhDtQCPE