javascript – Is Keycloack an IAM Tool like “Microsoft Azure Active Directory”?

I am new to this field, I am a front-end developer, but recently learnt of few terms – like “Keycloack” and “ping-IMS”.

Now I came to know that there are IAM tools like following:

• Microsoft Azure Active Directory;
• One Login
• AWS Verified Access;

I got a feel that ==> Keyclock or ping_Identiy is FREE or open-source, so I don’t think it does the same thing as — heavily paid services lilke MS_Azure_AD, or One_Login or IBM Identity and Access Mangement.

All these terms are pretty confusing to me. can anyone tell me — are all these things just the same?

Also, is there any difference between “SSO” and “IAM/IMS Tools”? (Identity Management tools). Thanks.