Reach measures how many unique accounts saw a piece of content, while engagement rate (typically likes, comments, shares, and saves divided by reach or followers) measures how actively people responded to it -- a smaller account with a high engagement rate often indicates a more loyal, responsive audience than a larger account with low engagement. Click-through rate (CTR) measures the percentage of viewers who clicked a link, which matters most when the goal is driving traffic to a website, WhatsApp chat, or online store rather than just building awareness. Instagram Insights (built into Instagram business accounts) and Meta Business Suite (which covers both Facebook and Instagram) provide free, built-in analytics on reach, engagement, follower growth, and content performance, meaning most small businesses do not need paid third-party analytics tools to get started. A simple monthly report should track a small number of consistent metrics over time -- rather than every available number -- so trends are visible and decisions (what content to make more or less of) can be made with confidence.