A Great Reference
What is an Overlocker versus a Serger?
I wondered that too and asked the question to find out overlocker is the European term and serger on our side of the Atlantic. Good to know!
The Big Book of Serging has details about the many stitch variations found on the BERNINA overlock machines. Each type of stitch, such as overlock, flatlock, coverstitch, etc. has a chart that shows the variations of the stitch and the most common settings used for those variations. There are also technique charts such as the one below showing the stitch settings for gathering and elastic applications.
Many folks fear the tension dial on their sewing machine. There’s a common phobia of getting the machine tension out of whack and not being able to fix it. But the ability to control and customize these settings is what makes an overlocker shine—changing these settings is how so many beautiful stitches are created!
Link to more here