PC connectivity
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USB A. A classic, mainstream USB port that has recently been losing ground to the more advanced USB-C port.
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USB-C. This connector differs from the classic, full-sized USB in much smaller dimensions, as well as a two-sided design that allows you to insert the plug in either direction. This interface is rarely found in desktop PCs, but is becoming increasingly popular in laptops, tablets, and phones. Note that the Type C standard only describes the connector design; The USB version (interface) is described in the paragraph below.
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Lightning. Apple's proprietary interface used in its compact devices (iPhone, iPad, and iPod touch) since 2012. In terms of application features, it is completely similar to the microUSB described above, adjusted for the fact that it is found only in “apple” gadgets and is not used by other manufacturers.
— Internal USB. A variation of the USB standard used to connect internal card readers (see "Type", "Destination"). It differs from external USB in a connector; you can connect a card reader with such a connection only to the connectors on the motherboard; it is not compatible with external USB ports. Other characteristics are completely similar to the corresponding external USB standard (see above).
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microUSB. A reduced version of the external USB interface (see a
...bove): the dimensions of such a connector are several times smaller than those of a full-sized one, which allows it to be used in portable equipment, in particular smartphones and tablets. Actually, card readers and hubs that use this interface to connect are usually designed for such equipment. Note that normal operation is possible only if the main device is capable of operating in USB host mode (this function is called USB On-the-Go).
— Wi-Fi. A wireless standard originally developed as a technology for building computer networks; later, Wi-Fi Direct technology appeared, which allows you to connect devices directly to each other. In card readers and hubs, this technology is found mainly among models designed for use with mobile devices (laptops, smartphones, tablets) that have a built-in Wi-Fi module. At the same time, the advantage over wired interfaces is not only the absence of wires and the corresponding freedom of movement, but also the possibility of simultaneously connecting several devices and exchanging data with them. And some models with Wi-Fi can even be connected to computer networks as full-fledged network drives. Of the shortcomings, it is worth noting the need for its own power source — either connecting to the network, which accordingly limits freedom of movement, or a battery that has a limited battery life (within a few hours).
— ExpressCard. A standard for connecting compact peripherals, mainly used in laptops. ExpressCard devices are usually 75x34x5 mm in size and are installed in a special slot in the computer case. Depending on the features of the system, it can provide speeds up to 2.5 Gbps, but in general it is less versatile and convenient than USB, due to which it is much less common and continues to lose popularity. Found exclusively in card readers (see "Type").
— Corporate outlet. Connecting external card readers (see "Intended use") through the original connector, which is usually used in the technique of a single manufacturer and does not comply with common standards like USB (see above). The scope of such models is quite limited, most often they are produced as additional accessories for certain models of portable equipment (for example, tablets).USB А
The number of USB inputs located on the case of the card reader or hub (see "Type"). The number of USB ports that you will have at your disposal after connecting the device depends on this parameter. "Pure" card readers and combined models, usually, have 1,
2 and even
3 USB inputs, while hubs have
4 or more ports.
HDMI
HDMI is the most popular of today's multimedia digital interfaces. It is specifically designed for HD content and delivers high-definition video and multi-channel audio over a single cable.
HDMI outputs are found mainly in hubs connected via USB Type C and compatible with the Thunderbolt interface (see "Connection"). Actually, to use HDMI, you will need to connect the device to the Thunderbolt v3 connector — "pure" USB Type C does not provide video transmission. This feature can be useful if the external screen is designed for HDMI connection, but there are no such connectors in the PC or laptop itself, they are busy or unavailable for another reason. At the same time, HDMI can be a different version, which affects the throughput. So to transfer video in 4K at 60 fps, you must have
HDMI v 2.0 or 2.1.
LAN (RJ-45)
The presence
of a LAN connector (RJ-45) makes it possible for the card reader/hub to work as a LAN adapter.
This port is commonly used for wired connection to computer networks. This connection may be preferable to wireless in some situations, but some devices (such as ultra-thin laptops) may not have a native LAN port. And in a PC, where such a port is usually installed on the back of the case, it can be much more difficult to get to it than to the USB connector. For such cases, card readers / hubs with a built-in LAN adapter are designed — usually, these are external devices connected via USB and capable of operating as an external network card.
Power Delivery
The technology allows you to work at higher voltage, thereby increasing the transmitted power.
USB hubs with Power Dlivery can not only charge smartphones faster, but also power more power-hungry devices, such as laptops.
Cable length
The length of the cable supplied with the device. Mostly relevant for models with a non-removable cable that cannot be replaced.
Material
The main material used for the body of the device.
— Plastic. Plastic is light, cheap, quite practical, incl. has good strength properties. In addition, it allows you to create cases of complex shape and almost any color.
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Metal. As a rule, aluminium-based alloys are used for metal cases. Such cases are much stronger than plastic ones, and also have a stylish appearance. On the other hand, in terms of impact protection, this material has no advantages over plastic, but it costs more, and it can weigh much more.