The word slider covers two different things in design. One is a control you drag along a track to choose a value, like a price filter or a volume bar. The other is a rotating banner that slides through a sequence of images or messages, often called a carousel.
Take the value control first. Think of the dimmer switch on a wall: instead of just on or off, you slide it to land anywhere in between. A range slider does the same on screen, which is why filters for price or distance often use one, where the rough position matters more than typing an exact number. Done well, the small movement and feedback as you drag is a nice micro-interaction that makes the control feel responsive.
There is a catch with the value kind, though. On a phone, a thin track is fiddly to grab with a thumb, and a slider with a wide range can make a single pixel worth ten euros. A keyboard user needs to reach the same control with arrow keys, which is easy to forget when you build a custom one. So for anything where the exact figure counts, pairing the slider with a typed field that mirrors it usually beats either one alone, and it keeps the control reachable for everyone.
Image sliders are more debated. They look impressive, but real data shows many visitors ignore them and most never see slides past the first. A strong single message often beats a rotating set, which is a recurring lesson in usability.
At TopDevs we use range sliders where they genuinely help people choose, and we avoid auto-rotating banners that bury your main message behind slides nobody waits for.
