To the OP:
There are three key ideas. First is that there are three big companies that store lot of records about your credit history. They are TransUnion, Experian, and Equifax., You will see them abbreviated here as TU, EX, and EQ. You can think of them each like a big warehouse where lots of information about you is stored. They might all have the same information, or it might be a little different. A printed summary of all your information at one of these credit bureaus is called a credit report. The three companies are called consumer reporting agencies (CRAs) or credit bureaus.
Second, because all that information could be very long and complicated, a number of companies have created big computer programs that can look through all that information and turn it into a single number, most often a number between 300 and 850 (roughly). That is called a credit score. Each company might have several different computer programs that assess your information in slightly different ways. These big computer programs are called credit scoring models or algorithms.
FICO is a company that makes many different scoring models. Another company makes a model called VantageScore. These are the two most important companies that make scoring models. But there are still others.
Third, there are "third-party" companies that can give you your score, by taking a particular scoring model and applying it the data of one or more CRAs or credit bureaus. Credit Karma, for example, is free and uses the VantageScore 3.0 model on the TU and EQ data. Discover uses the FICO 8 Standard model on the TU data. myFICO charges a fee but gives you many FICO scores on all three CRAs.
So when you are looking at a score, you need to look at the source of the data (TU, EX, or EQ) and also the scoring model that is being used.
No model or bureau is the "right" one as an absolute. They can all be useful if you compare them against themselves over time: for example, if you compare your TU score from Karma against itself over six months and see that it is gradually going up.
All of the models are different but they all care about a lot of the same things: keeping your credit card debt low, paying your bills always on time, etc.
In your case, your scores are low, but they are all pretty close to each other. What would help you is to learn the kinds of habits that make your credit scores and reports look good regardless of what model is being used.
Let me know if that all makes sense.
