The rear cameras of mobile devices use mainly a LED flash. It may arrive in a single, dual- or multi-light setup and in different arrangements. Information about the width, i.e. the horizontal side of the device when it is used in its standard orientation. The Samsung Galaxy Xcover 4 has models SM-G390F, SM-G390W, And SM-G390Y. This phone has been succeeded by the Xcover 4s. Information about the number of pixels per centimeter (ppcm) or per inch (ppi) of the display. The higher the pixel density, the more detailed and clearer is the information displayed on the screen.

Networks A mobile (cellular) network is a radio system, which allows a large number of mobile devices to communicate with each other. GSM Information about the process technology used in manufacturing the chip. The value in nanometers represents half the distance between elements that make up the CPU. Specific Absorption Rate (SAR) The SAR rating shows the amount of electromagnetic radiation absorbed by the human body when using a mobile device, expressed in W/kg. Head SAR (EU) Information about the sensor type of the camera. Some of the most widely used types of image sensors on mobile devices are CMOS, BSI, ISOCELL, etc.

Display

System on Chip (SoC) A system on a chip (SoC) includes into a single chip some of the main hardware components of the mobile device. SoC Even if Samsung's Galaxy XCover 4 is not quite as resistant as it appears, it is protected better than many other very sensitive smartphones. The robust plastic casing does not look bulky and even the battery can be replaced. Water and dust protection have been increased compared with the predecessor, and the speaker now functions impeccably when the handset is wet. After using it in water, we found a drop of water under the rear cover. Thus, the device should be dried separately here. Information about the number of pixels on the horizontal and vertical dimensions of the photos taken by the front camera, indicated in megapixels as well. The device is also MIL-STD-810G certified, which means that in theory it should easily withstand salty air, high or low temperatures or low pressure. However, according to Wikipedia, the test conditions for consumer devices are not controlled since it is a military standard. Samsung can thus specify its own test criteria – this should be kept in mind. According to the manufacturer, the smartphone had to pass the following tests to achieve the MIL-STD 810G certification:

talk time is the time period a battery charge will last, if one is constantly talking on the phone in a 3G cellular network. The capacity of a battery shows the maximum charge, which it can store, measured in mili-Ampere hours. A CPU core is the processor unit, which executes software instructions. Presently, besides single-core processors, there are dual-core, quad-core, hexa-core and so on multi-core processors. They increase the performance of the device allowing the execution of multiple instructions in parallel. One of the main characteristics of the display is its type/technology, on which depends its performance. Estimated volume of the device, calculated from the dimensions provided by the manufacturer. Applies for devices in the form of a rectangular parallelepiped.Battery The batteries of mobile devices differ in capacity and technology. They provide the electrical charge needed for the functioning of the devices. Capacity The SAR head rating shows the highest level of exposure to electromagnetic radiation measured when the device is held next to the ear in a talk position. In Europe, the SAR limit for hand-held mobile devices is set to 2 W/kg per 10 g of tissue. This standard is specified by the CENELEC, complies with the IEC standards and follows the ICNIRP Guidelines 1998. Display The display of a mobile device is characterized by its technology, resolution, pixel density, diagonal length, color depth, etc. Type/technology Information about additional software and hardware features of the rear camera which improve its overall performance.