A slider can refer to different things depending on the context. Here are some definitions:

• Slider sandwich: A slider is a small sandwich, typically around 2 inches across, made with a bun. It can be served as hors doeuvres, snacks, or entrées. The name "slider" is believed to have been first used to describe the onion-steamed small burgers at White Castle restaurants).

• Slider in web design: A slider is a design element used to display images and videos on a website. It works like a slideshow, showing one image or video at a time. The content changes after a few seconds or when the visitor clicks to view the next one. Many WordPress slider plugins allow you to place sliders on your home page, landing pages, posts, and almost anywhere you want on your site. Sliders are a great way to show off your most important content in an attention-grabbing way.

• Slider pitch: A slider is a breaking pitch that is thrown faster and generally with less overall movement than a curveball. It breaks sharply and at a greater velocity than most other breaking pitches. The slider and the curveball are sometimes confused because they generally have the same purpose -- to deceive the hitter with spin and movement away from a pitchers arm-side.

In summary, a slider can refer to a small sandwich, a design element used to display images and videos on a website, or a type of pitch in baseball.