I am trying to run an outdoor cable about 120m and was informed that I need to have splicing and a termination box. But based on this picture it seems I can just have this kind of connector which is 120m long and plug into a SFP module on both end?
Well, you could - provided you can find one long enough and appropriate for outdoor usage. The outdoor cables must sustain weather conditions, especially UV radiation coming from the Sun - they are usually black, as the jacket colors usually are meaningful (e.g. the patchcord from your photo is apparently some multimode).