Battery The batteries of mobile devices differ in capacity and technology. They provide the electrical charge needed for the functioning of the devices. Capacity

CPU is the Central Processing Unit or the processor of a mobile device. Its main function is to interpret and execute instructions contained in software applications. The device's storage configuration could be more generous, but its extensive operating system and quite useful primary camera are convincing. The input options are diverse, the screen is appropriate, and the performance sufficient for daily routine. The battery life also fits well to the good overall impression. We did not like the handset's sound quality and gaming performance as much, though. The aperture (f-stop number) indicates the size of the lens diaphragm opening, which controls the amount of light reaching the image sensor. The lower the f-stop number, the larger the diaphragm opening is, hence, the more light reaches the sensor. Usually, the f-stop number specified is the one that corresponds to the maximum possible diaphragm opening. Design Information about the dimensions and weight of the device, shown in different measurement units. Body materials, available colors, certifications. Width Information about additional software and hardware features of the rear camera which improve its overall performance.The capacity of a battery shows the maximum charge, which it can store, measured in mili-Ampere hours. 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. 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 Samsung Galaxy Xcover 4 is an Android smartphone produced by Samsung Electronics and released in April 2017. It is the successor to the Samsung Galaxy Xcover 3. The Xcover 4 is waterproof and dustproof designed around the IP68 specifications. Similar to the CPU, the GPU consists of processing units called cores. They handle the computation of graphics in various applications.

Focal length is the distance in millimeters from the focal point of the image sensor to the optical center of the lens. The 35 mm equivalent indicates the focal length at which a full-frame camera will achieve an angle of view that's the same as the one of the camera of the mobile device. It is measured by multiplying the native focal length of the camera by the crop factor of the sensor. The crop factor itself can be determined as the ratio between the diagonal distances of the image sensor in the 35 mm camera and a given sensor. 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. 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) Display The display of a mobile device is characterized by its technology, resolution, pixel density, diagonal length, color depth, etc. Type/technology The instruction set architecture (ISA) is a set of commands used by the software to manage the CPU's work. Information about the set of instructions the processor can execute.