Your home’s main door is the most important line of defence. So it goes without saying that your door and its lock must be robust and strong as that’s the main safety barrier standing between you and the outside world. Though locks are important, it becomes a pivotal point in apartments, where hundreds of people share common spaces.source https://timesofindia.indiatimes.com/life-style/home-garden/5-types-of-main-door-locks-and-which-one-is-perfect-for-apartments/photostory/127917005.cms