You got a moderator message, or were suspended
This is something that happens very rarely. At the time of this writing, the site has been around for 7 years, has over 30 000 users, and the number of users who have ever been suspended (except spammers) has a single digit. The typical process is: people come here, do what they are accustomed from other situation, happen to “bump” against a rule. Moderators or high-rep users explain the relevant rule, clean up any content (e.g. by closing the question), the user learns from the situation, and everything is fine. There is nothing wrong with that.
If a moderator sends a message (to your registered email account), optionally with a timed suspension, it means that the moderators find your behavior so disruptive that the site has to be protected from it. This usually happens for one of these three reasons:
- You intentionally abused the system in some way. For example, you could have created a second account which upvotes all the answers of the first one (“sock puppet”) or asked your best friend to do that with their account (“meat puppet”).
- You disagree with the rules and think rules shouldn’t apply to your posts. When others ask you to honor the rules, you argue against that, accuse the people who are trying to explain the rules of having a personal grudge against you, or in principle agree with the rules, but every time some of your content is changed because of them you argue that the rules were misinterpreted and your content should be left as it is1. Or you do not argue at all, but ignore any suggestions and keep posting whatever you want as if the rules do not exist.
- Some of your content is good, but some is excessive self-promotion without disclosure.
A short suspension is the last chance you will get to change your behavior. If you do not learn from it, our community prefers to lose your contribution, even if part of it is good content, than to have to constantly deal with drama and cleanup.
1 This does not mean that you cannot complain. Mistakes happen, there are some differences in the ways different community members and moderators interpret the rules, and those interacting your post may overlook a good, less-destructive way to solve the problem. So you can take each case to Meta or to the team of StackExchange, the company which runs the site (the moderators are not employees of the company, they are unpaid elected volunteers from the community). What I mean is that, if you complain about a substantial proportion of the corrections of your content, and it is multiple people correcting you, the chance is that this is no mistake and you have misunderstood how the site works.