Know the password of your WiFi network

Many times my computer is connected to a WiFi network but I don't remember the password for it now. This is something I have experienced a lot. Often, I am using the teacher's WiFi network of my college and the administrator himself enters the password without revealing it to me, and sometimes some of my cousins do the same. Faced a similar situation and you want to connect a second device but don't know or remember the password? You can obviously ask the admin about the password or you can find it yourself.