At first, you might think that a Droid is an Android phone that's sold by Verizon Wireless. But not all Verizon Android phones are Droids, and Droids are made variously by Motorola, HTC and now Samsung. You could hazard a guess that Verizon reserves the Droid handle for its top-of-the market phones, but that's wrong, too: For one thing, the top of the market changes roughly every month.
Compare the brand-new Droid Charge with the hardly-out-of-diapers, not-a-Droid HTC ThunderBolt. Both are Android 2.2 (Froyo) phones that feature Verizon's wicked fast 4G LTE data network. They are virtually the same size (the Charge is 0.3 in. longer). Both have a 1.3-megapixel front-facing camera and an 8-megapixel main camera with 720p video recording. Both have 1GHz processors -- the Samsung Hummingbird on the Charge, and the Qualcomm MSM8655 on the ThunderBolt.
Yet there are differences. The Charge has Samsung's superb (and less heavy) 4.3-in. Super AMOLED Plus screen, which gives it a comparatively light weight of 5 oz. (the ThunderBolt is a hefty 6.2 oz.) In fact, despite HTC's positioning as a video display device, it is the Charge that has an HDMI output, as well as the better screen -- it's sharper, faster, more vivid and more easily seen in bright sunlight.
The Charge also has a larger battery: 1600mAh compared to the ThunderBolt's 1400mAh. Combined with the AMOLED screen's lesser power requirement, this will likely translate into longer battery life. There's really no such thing as "typical" phone usage, but I got close to a full day's use out of it. If you run the data network a lot, or if you use the tethering feature, you won't.
The Charge runs counter to most current phone styles by using separate physical buttons across the bottom of the phone, rather than capacitive touch buttons. They aren't backlit, which is inconvenient. (On the other hand, the backlighting on most capacitive buttons is nothing to write home about, so it's not much of a loss.)