ᐅ Connection of the lower end of the kitchen sink drain to the waste pipe

Under my kitchen sink, at the connection between the sink drain and the waste pipe, the drain pipe has come loose. I see a rubber seal positioned between the end of the drain and the pipe.

I don’t know how the drain pipe came loose. As a non-professional, can I reconnect this drain pipe myself? If yes, how? (Please avoid technical jargon, as I am a layperson). The drain pipe is made of plastic.