The short version
What sewer pipe lining is, and what it is not
Every buried pipe eventually does one of three things: it leaks at the joints, it loses its shape, or it collapses. Lining is the answer to the first. A tube of felt or fiberglass is wetted out with resin, pulled or inverted into the existing sewer, drain or storm line, inflated so it presses against the old wall, and cured in place with hot water, steam or ultraviolet light until it is a rigid pipe of its own. The clay, cast iron, concrete, Orangeburg or corrugated metal that was there before becomes a mold and nothing more. Roots lose the joints they were growing through, groundwater loses the cracks it was pouring in through, and the rough, scaled interior that was catching grease and paper is replaced by a smooth one.
Lining is not a cure for geometry. A liner copies the pipe it cures in, so a sag that holds water before lining holds water after; a section crushed by a driveway or sheared by moving ground cannot be passed at all. Those lines need pipe bursting, which pulls a new polyethylene pipe through the old route, or a sectional dig where nothing else will work. And a single bad joint in an otherwise sound run does not need a full liner; a short sleeve cured over that one spot fixes it for a fraction of the cost. Which of these applies is decided by one thing, and it is not a price sheet: a camera inspection of the actual pipe, recorded, with every defect located from the surface.
This site exists to explain those choices plainly, for a homeowner with a backup, a property manager with a restaurant row, or a public works director with a culvert, and to connect you with an installer who has been checked out before the listing went up.