In this case, you will want to choose 'UPLOAD' (use local saves), in order to copy your local file up to the Steam server. In most cases, it you are playing on one system, if Steam prompts you with the choice, usually the local file is further progressed than the cloud save.
Should you receive this option, be very careful about which choice you select, as the selected file will overwrite (delete) the other file. Should the Cloud Save fall behind the Local Save, the next time the game is launched, Steam will ask which version the player wants to use. The cloud version of a player's save file can fall behind the progress of the local file if the player either loses connection briefly, or is playing in offline mode. In most cases, this should work to protect your save data, but in some circumstances, can cause the opposite. In most situation, the cloud save functions as a back-up, and can allow you to regain your progress in the event of either a loss of data on your system, or if you want to play the game on a second system with the same save file. Borderlands 2 for PC saves in two locations, it saves your progression locally on your PC, and if you are connected to the internet, it will create a back-up cloud save through Steam. We are aware of an issue which is affecting some PC players, which may cause a loss in progression.