At times as rooms were illuminated mainly with light bulbs, it sufficed to use watts as an indication of brightness. This changed with the introduction of LED as light source.
In order to compare the brightness of light sources with each other, the term lumen is used. The luminous flux lumen is the unit for all of the light which irradiates a light source in the room. Thus it describes the amount of light.
A 25 watt light bulb emits a luminous flux of 200 lumens. This corresponds to 8 lumens per watt.
With an LED as light source, the energy balance is much more efficient. For the same brightness only one LED of about 2-3 watts is required. An LED achieves 100 lumens with 1 Watt.
The table gives you the possibility to compare different lamps.