Often times, the difference between and R, or Reflector, lights and PAR lights can go unknown. The main difference between the two is that R bulbs offer more soft-edged light while PAR lamp offer more precise angles. The glass used for R lamps is also thinner, making these bulbs more suitable for indoor use. R bulbs also produce less shadow than PAR bulbs.
Lumens
With new light bulbs, shopping by lumens is more important than shopping by watts when choosing which energy-efficient bulb to purchase. While wattage measures the amount of energy required to light products, lumens measure the amount of light produced. This means that the more lumens the product has, the brighter the light source is. Instead of buying products based on how much energy they consume (watts), consumers should consider how much light they give us (lumens).
Wattage
Wattage is the measure of the bulb's energy consumption - not how much light it puts out. Energy-efficient bulbs use fewer watts to give off the same amount of brightness (lumens). Because of this, LEDs (which have typically low wattages when compared with lumens) not only help reduce energy usage but also lower electric bills.
Color Temperature
Color temperature refers to the color appearance of the light that comes from a light source. It's an important performance characteristic to asses when evaluating bulbs because the color temperature creates the mood of the space you are lighting and can thus influence buying behavior or work performance. The apparent color of a light source is measured in Kelvin. The higher the Kelvin temperature, the whiter the light.
Dimmable
Dimming LED bulbs gives you the same kind of flexibility and control you can expect from your incandescent bulbs. With so many improvements to this technology, it has become easier to find an appropriate energy-efficient replacement to work with your dimming system. You will save more energy and find a large reduction in your electrical bill while still getting the amount of light that you need with dimmable LEDs. Customers also use these dimmers for track lighting--where desirable ambient light levels are needed but where a dimmed light setting is also desirable.
Energy Star Rated
Products with Energy Star labels meet the energy efficiency requirements set forth in ENERGY STAR product specifications. Some guidelines include contributing significant energy savings nationwide, delivering the features and performance demanded by consumers (in addition to increased energy efficiency), and energy consumption and performance being measured and verified with testing.