A handset is a component of a telephone that a user holds to the ear and mouth to receive audio through the receiver and speak to the remote party using the built-in transmitter.
A mobile phone does not require a base station and communicates directly with a cell site in designated frequency bands.
A graphic symbol that designates a handset is used on cordless and mobile phones to specify placing or ending a telephone call.
Usually a button with green upright (off-hook) handset icon is used for starting a call, and a red lying-down (on-hook) handset is used for ending a call.
[1] Unicode has the handset symbol U+1F4DE š TELEPHONE RECEIVER commonly faced rightwards to use with face emojis, and also symbols with specified direction: U+1F57B š» LEFT HAND TELEPHONE RECEIVER, and U+1F57D š½ RIGHT HAND TELEPHONE RECEIVER[2].