It's not bad. The nVidia GT 745m is a mainstream type of graphics chip which should be able to run many games at 1366x768 resolution using medium settings. But graphically demanding games likely means you need to drop it down to low settings for good performance.
Older games and less graphically demanding games may be able to be played at 1600x900 with medium quality graphics.
Running games at full resolution (1080p) will likely require a lot of graphics tweaking if the game allows you to do so. For example, it could be possible to play Skyrim at 1080p with a lot of tweaking in the graphics options and also searching for mods that can help improve performance in the game. Plus tweaking the *.ini file to disable grass and shadows...