It is sent from the user's mobile phone and is directed towards a network, which could be for sending a text message to another phone, accessing the internet, or interacting with an application. 

• Initiation from Mobile Device: MO messages are initiated by the mobile user. This contrasts with "Mobile Terminated" (MT) messages, which are messages sent to a mobile device.

• SMS and MMS Messaging: In the context of SMS (Short Message Service) and MMS (Multimedia Messaging Service), an MO message is a text or multimedia message sent from a mobile device to a recipient, which can be another mobile user or an application.

• Data Services: MO messages also include data services such as email, web browsing, or app usage on a mobile device, where the data request originates from the user's phone.

Mobile Originated messages are integral to the functionality of mobile networks, facilitating a wide range of communication and data services for mobile users.