Pre-Service History Choice Mass Effect Background Explained

Starting out with Mass Effect, players need to create a character's appearance and profile. A character's class and customized looks define a player, you will also choose a pre-service history and psychological background.
Pre-Service History Choice Mass Effect Background Explained
At the start of the game after customizing the character, players need to select a pre-service history that gives more background to their character. Pre-service history changes the nature of the game within the dialogue between two or more characters of the story and certain actions. Here is a brief background on the three pre-service history characteristics:
Spacer
The background history of a Spacer starts with the character's childhood. Both of the character's parents were always going to ships or space stations, never staying in one location or having a place to call home. Of age, the character enlisted at a young age in the military.
Earthborn
The characteristics of this background history are rougher on Shepard. Earthborn character background history is that they were raised as an orphan surviving the streets of the great metropolises. Involved with gangs and crime, you eventually escape by enlisting into the Alliance military.
Colonist
The background history of a Colonist means they were born and raised on the space-country side. A place called Attican Traverse, a raid of slavers attacked and killed your family and friends. An Alliance patrol saved you and inspired you to join the military years later.
Choosing any of the three pre-service characteristics affects the game by a small margin. Players will experience different dialogue and consequences but won't affect the actual narrative Mass Effect brings.