A credit score is a three-digit summary of your credit history, generated from the information in your credit report. The most common scoring model, FICO, ranges from 300 to 850. Lenders don't use score as a pass/fail line so much as a way to price risk — generally, the higher your score, the more loan programs are open to you and the better the terms those programs are likely to offer, though actual terms always depend on the lender and the full loan file.
Your score is built from five ingredients, in roughly this order of importance: payment history (do you pay on time?), amounts owed (how much of your available credit are you using?), length of credit history, new credit (how many new accounts or hard inquiries you've opened recently), and credit mix (the variety of account types you manage). Payment history and amounts owed together make up the majority of the score, which is why they're the highest-leverage places to focus.
You're entitled to a free copy of your credit report from each of the three major bureaus — Equifax, Experian, and TransUnion — through AnnualCreditReport.com, the official site authorized by federal law. Pulling your own report is a "soft" check and never affects your score. Reading it before a lender does is one of the simplest, highest-value habits a future buyer can build, because it's the only way to catch an error, an old collection, or an account that isn't yours before it becomes a surprise mid-application.
It's worth knowing that mortgage lenders often look at a slightly different version of your score than the one a free app shows you — mortgage scoring models can weigh factors differently than the consumer-facing scores from credit card apps or budgeting tools. Treat those numbers as a helpful general direction, not the exact figure an underwriter will see.
None of this is about chasing a "perfect" score. It's about understanding your own starting point clearly enough to make informed decisions in the Prepare stage that follows — and about avoiding the handful of moves (like opening new credit or missing a payment) that can quietly work against you while you're getting ready to buy.