Most LED lights for traditional home and office use will dim when used on a dimmer ... although if you need this function, make sure to verify that a lamp is rated as dimmable before you purchase it. Beyond this blanket statement, we would add that you'll need a compatible dimmer. LEDs may dim on non-compatible dimmers, but may also have some issues, possibly as simple as not dimming as much as you'd like.
Some LEDs, however, are simply not meant to dim. Yes, there are household LEDs that don't dim in order to keep costs down. But others don't dim because dimming isn't common in their application. This is true of high bay replacements like corn cob LEDs. So what happens if you do try to dim this kind of bulb? You get the sort of flashing / strobing seen in this short video.