Well its like a text or chat msg in principle but its waaaay different. When R2 interfaces with a computer network that has an on board AI (like the cloud city network that told him the falcons hyperdrive was disabled) he talks to the AI within the network to find what he needs or do what hes trying to do. When R2 interfaces with a network with no AI (like the death star computer imperial network) he has to go through the file structure of the network to find what hes looking for or do what hes trying to do. When R2 interfaces with a binary machine node (open a door or activate industrial machinery) he has to go through the program functions of the device to activate the one he wants to in order to open the door or shut down or activate something. Speed depends on size and organization of the network and R2's processor rate