While internal hardware varies, most have an electronic visual display, either backlit LCD or OLED or Hologram.[4] Some use transflective or electronic paper, to consume less power. Most have a rechargeable battery. Peripheral devices may include digital cameras, thermometers, accelerometers, pedometers, heart rate monitors, altimeters, barometers, compasses, GPS receivers, tiny speakers, and SD cards, which are recognized as storage devices by many other kinds of computers.
In 2003, Fossil released the Wrist PDA, a watch which ran the Palm OS and contained 8 MB of RAM and 4 MB of flash memory.[27][28] It contained a built in stylus to help use the tiny monochrome display, which had a resolution of 160×160 pixels. Although many reviewers declared the watch revolutionary, it was criticized for its weight (108 grams) and was ultimately discontinued in 2005.[29]

The primary differences with the Classic versus the standard include, first off, that this model lacks LTE. That, however, does mean that the Classic is built from a more premium “Titanium Grey” shell which has a bit less sporty look. A leather band is also installed out of the box rather than the silicone one found on other models. Pricing on the Huawei Watch 2 Classic is a bit higher than the standard model, asking $369 from retailers such as Amazon and Best Buy.
The Apple Watch Series 4 is now on sale, and it's the best smartwatch you can buy right now. The redesigned device, which starts at $399 for the GPS model and $499 for the cellular version, is the best smartwatch you can buy. It has a larger display and slightly bigger case size while retaining the same rounded square design the watch is known for. Even more importantly, Apple received FDA clearance for a new electrocardiogram feature that can take a 30-second EKG and diagnose atrial fibrillation.