Dimmable (DIM) indicates a light source whose light intensity can be varied. For LED items, the information is shown on the item’s page. Where it is stated “with dimmable driver”, it is possible to choose a driver from those indicated, able to vary the intensity of the LED component. If “depends on variants” is stated, then you will have to check the specific electrical part, and if it's stated in the description (TRIAC as an example) or there are dimmable drivers available among the ones indicated, then it will be dimmable. For items with a bulb holder, a dimmable bulb compatible with the control system in use can be utilised.