For future reference this topic is discussed a lot here and a quick forum search will usually provide the answers you seek.
You have two broad categories of credit scores: 1) FICO scores by the Fair Isaac Corporation; and 2) FAKO scores which is basically everything else. Most FAKO scores are for educational purposes and not used in lending. However, some FAKO scores like the Vantage score are used by a tiny fractional minority of lenders (pretty much non-existent). Some variant of a FICO score is generally used by most major lenders. However, many of these lenders use internal scoring systems and other factors beyond just your score when making lending decisions.
The world would be very simple if we only had the FICO/FAKO distinction. Unfortunately, we have dozens of FICO scores. You have different FICO scoring models like the FICO 98, FICO 04, FICO 08, and FICO 9 models. Within each of these models we have various industry enhanced variants like auto enhanced and bankcard versions. These enhanced versions typically run on a 900 scale while regular FICO versions only go up to 850 (some FICO variants below FICO 08 go up to the 830s or 840s only).
When applying for a home loan, a FICO 08 score is usually useless because most home lenders pull FICO 04 or 98 scores. When applying for a credit card, a FICO 98 score is usually useless because most lenders pull the FICO 08 score. To make matters even more confusing, not all lenders follow these general patterns and some pull bankcard enhanced FICO 08 scores for credit cards (minority). To make a long story short, unless you know what score the lender is going to pull, knowing your score is not very useful.
The important thing is to pull your credit report and make sure everything looks good. No missed payments, no lates, no public records, a decent credit mix of revolving and installment accounts, a moderate to long credit history, low utilization of revolving debt, and such factors that impact scoring. If all these factors are excellent, your score will likely be excellent across all models. When one or more of these areas are not so good, your scores will start varying across FICO scoring models because some put more emphasis on areas like credit utilization and other such factors.
Recently, myFICO started providing more than just the FICO 08 score to those who subscribe to the 3 Bureau Monitoring Service. You can also see some enhanced variants and older variants of your EQ and EX scores (only FICO 08 for TU). While I don't recommend you subscribe to it right away, if you plan on taking a particular loan (e.g. home loan) it might make sense to subscribe. Otherwise, just pull your credit reports and work on getting your reports to look good. If you do that, all your scores will improve across all scoring models. CK is useful for reports and the Vantage score is useful to see progression of the score. Just don't focus too much on it and bear in mind that some changes might result in a Vantage score moving in the opposite direction of a specific FICO score. But in general, if your Vantage score keeps going up, chances are your FICO scores are too.
