Either intentionally or in error, you simply didn't handle the case at the time. Unfortunately the prosecutor and judge don't know why you didn't show up, even if you had a really good reason. Somewhere in a courtroom days, weeks, months or years ago, your case was called and you weren't present. The judge issued a warrant for your arrest, and it's been sitting in that status this entire time.
You have even been hired for jobs, been pulled over and lived a relatively normal life with this warrant; this doesn't mean that it won't impact your life at some point. Chances are if you're reading this right now, something has motivated you to try to clear up a warrant on a case. Well that's just the first step.
Hiring a lawyer to help you clear up a warrant may or may not involve you coming to court with the lawyer and explaining yourself to the judge with the help of your lawyer. You need to convince the judge by appearing, they should cancel the warrant, and agree to let you eventually leave the courthouse, and trust you again.
When you have a warrant, it usually means your case still needs to be handled in a pretrial stage, you missed sentencing or you violated probation or didn't pay some fines on a ticket. Depending on the status of your case, you may be starting at square one or in the middle or end of the case. People are not rewarded by fleeing for days, weeks, months and years, so be prepared to take it seriously and work closely with your attorney to figure out your options, and put this issue behind you.