Generally speaking, the higher the reputation with a Faction, the more they like <player>. Conversely, the lower the reputation, the more <player>'s disliked. Good reputation leads reputation leads to (more, higher-paying) missions, improved trading discounts & the availability of Licenses in the more lawful systems of Albion and Omicron Lyrae (resulting in increased mission variety, rewards and cash bonuses for shooting hostiles), and not getting shot in the face.
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