Concentration is how much sits in the fund's largest positions - the top-10 weight. High concentration means stronger conviction but more single-stock risk.
Active share measures how different the portfolio is from its benchmark (0% = identical to the index, 100% = totally different). A low active share on an "active" fund charging high fees may signal closet indexing - you're paying active fees for near-index returns. Gajamudra surfaces both on every fund page.