Framed vs. Frameless Shower Door
The two dominant US shower door constructions — framed doors have a metal perimeter frame with built-in seals; frameless doors are bare glass with separate clip-on seals.
Framed doors have an aluminum frame around the glass; the seals (usually a vinyl strip called a "wipe" or "fin") are often built into the frame's channel and get replaced as a strip that slides into that channel.
Frameless doors are thicker glass (typically 3/8" or 1/2") with no surrounding metal frame, held by hinges and clips directly on the glass. All the sealing — bottom sweep, side wipes, bulb seal at the hinge/strike side — is done with separate parts clipped or taped directly to the glass edge. Frameless is the more common style in new construction and remodels since the 2010s; framed is still common in older homes and budget installs.