Most permanent systems start with a slim aluminum or vinyl channel, sometimes called a track, that runs along the fascia board just under the edge of the roof. The lights clip or slide into that channel. The channel does two jobs: it holds every light at the same angle so the line looks straight from the street, and it shields the wiring from direct sun and rain.
Channels usually come in a few stock colors, and a good installer matches the channel to the trim. On a white fascia you use a white channel; on a dark bronze gutter line you use a dark one. Some systems can also be painted to match unusual trim colors.
The channel is fastened to the fascia or to the face of the gutter with short screws, roughly every couple of feet depending on the system. Nothing goes through the roof shingles. On most homes the work is done from a ladder or a lift along the eaves, and a typical home takes 8 to 10 hours to install.
Wiring runs inside or behind the channel to a power supply, which plugs into an exterior outlet or a dedicated circuit, often near the garage or under an eave. A small controller sits next to the power supply. From there a signal tells each light what to show.
Where the roofline jumps from one level to another, the installer runs a short connector cable between sections. Corners, peaks and gable returns each need a little planning so that the light spacing stays even through the turn.
By day the install is basically invisible. No ugly holiday lights hanging all year. From the curb you see a thin line along the fascia that reads as part of the trim, especially when the channel color matches. Up close you can see the small lenses, but from the driveway most people cannot tell the lights are there until they come on.
That is the main difference from seasonal strands. Clip-on holiday lights droop between gutter clips and catch leaves. A fixed channel keeps every light in a straight, even row, day and night.
Turned on, the line traces the roof shape. A simple gable reads as a clean triangle. A complex roof with several peaks and dormers looks like an outline drawing of the house. In everyday white, many owners run the lights at a low level as accent lighting. On a holiday, the same line can show solid colors, alternating colors, or slow movement.
Expect a lifespan of 10 to 20 years. LEDs do not burn out the way old bulbs did; they fade slowly over time. Day-to-day upkeep is light: an occasional look after a big storm, and clearing any branch that rests against the channel.