Sergers are wonderful machines that can do a variety of sewing tasks... not all sewing tasks but many unique to a serger. There are many commonly asked questions by people who sew but have never sewn on a serger or overlock machine. Learn and become an educated consumer about sergers, the number of threads a serger uses and explore serger options before you buy a serger.
You aren't the first person to have questions about what a serger is and what it does. This article is aimed at answering all of your questions about understanding a serger or overlock sewing machine.