Standard: These are the most popular. Because the standard white model can be used in almost any kind of application. They are robust enough to handle a very high discharge current for example in powerful flashlights and RC cars. In combination with their life cycle rating of 2100, you can't go wrong with the standard models in almost all cases. They power 1900mAh minimum capacity for their AA and 750mAh for their AAA batteries. They are good for Flashlights, RC Toys, Cameras, Camera Flash, Radios, MP3 players and much more. See more details on the Eneloop tests page. Lite: These cells are rated for 3000 cycles (for the Japanese model) or 5000 cycles (for the Chinese model) but have a much lower capacity at 950 mAh for the AA and 550 for the AAA. Besides using them in low drain devices such as clocks, alarms, remote controls, and such, these are the only batteries really recommended for DECT phones. (even though the standard Eneloops are sometimes recommended as well, Lite cells make much more sense). Standard and Pro batteries are not recommended for this. Because the phones usually stand in a charging cradle with a continuous trickle charge. LSD batteries do generally not like that, but the Lites are the only ones to consider for that kind of use. Pro: It's called the High-End battery in their line-up. Featuring the highest capacity with an LSD rating of 85% in 1 year. Being a high capacity cell, they are only rated for 500 cycles. If you need the extra power and the extra capacity these are the ones to get. Especially in multiple cell configurations. If you have 4 batteries parallel you gain the capacity of 1 extra std cell in comparison with 4 std cells parallel. These are highly recommended for Flashlights, Camera strobes, and other powerful devices. These are NOT recommended for DECT phones or other devices with a continuous charge current. Another thing you have to consider when buying these Pro batteries is the fact that they are just a tiny bit wider than the standard ones which may result in not fitting. This is such a tiny bit of difference that most people do not notice it. Sanyo noted that they do not fit the AA to D size spacers (NCS-TG-D).  They may have changed this with their latest Panasonic upgrade (BQ-BS1E). Be careful, these battery jackets are easier to damage! Read more on the dedicated Eneloop PRO page.