What is an on-demand system for booking taxis or deliveries?

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An on-demand system for booking taxis or deliveries is an application or platform that allows users to request a ride or delivery service instantly and on-demand through their mobile devices or computers. These systems typically connect users with nearby drivers or delivery personnel and enable them to track the status of their ride or delivery in real-time. Popular examples of on-demand systems for booking taxis or deliveries include Uber, Lyft, Grab, Gojek, DoorDash, and Postmates.