A competitive advantage is typically defined as some internal resource of capability to produce a feature. Features fall into two categories: hygiene features and differentiating features.
A hygiene feature is something that confers absolutely no advantage in being able to deliver this. Hygiene features can be thought of as table stakes to just play the game. However there is an advantage in being able to deliver hygiene features at lower cost because a cost advantage can be turned into other differentiating features such as price etc.
A differentiating feature is an advantage that your company is uniquely suited to deliver. You should consider issues of importance to the customer, such as ease of use, speed of delivery etc.