Everyone basically knows what jurisdiction means from what they see on TV and other media. Obviously lawyers have to make it just a bit more complicated. There's actually two basic types of jurisdiction: (1) subject-matter jurisdiction and (2) personal jurisdiction.
Subject-matter jurisdiction is a court's power to hear a particular type of case. For example, in Nebraska, only County Courts hear probate cases (see subsection 1). Lawsuits exceeding $57,000 (see subsection 5(b)) are only heard in District Court (as of the writing of this).
Personal jurisdiction is a court's power over the parties before the court. This has nothing to do with what type of case it is, but everything to do with whether the Plaintiff properly followed the law for serving a Complaint and Summons (and some Constitutional considerations).