Answer :

The very first video games were the result of experiments and hobbies in the 50s and 60s, created within university confines. They were mostly created out of boredom and were no more sophisticated than monotone blocks or blips on Cathode Ray Tubes. Their function was simple: to facilitate competition between others or with oneself.
Soon the concept became commercial, and as time went by, competition, consumer demand and technological advances fueled the evolution of video games. Increases in storage permitted more content. Greater memory and processing speeds allowed complex movement and visual effects to improve. Simple moveable objects gave way to vaguely recognizable characters. A single screen of activity grew into "side-scrolling," and eventually movement through simulated three-dimensional space. Inevitably, all these developments became the source for the growth of narrative in video games.