A feature is a fact about a product (a phone has a 5,000mAh battery); a benefit is what that fact means for the customer (you can go a full day of calls and browsing without charging) — the common sales principle 'features tell, benefits sell' captures the idea that customers buy outcomes, not specifications. Strong product knowledge means being able to answer common questions accurately and honestly, including admitting when a product is not the right fit for a particular customer, which builds more trust than overselling something that will disappoint them later. Salespeople who only recite features often lose customers who cannot see why those details matter to their specific situation, while those who connect features to real benefits make the value obvious.