Card reader
A device for reading memory cards, most often in SD format. This feature is especially useful for exchanging information with some types of modern electronics: almost all cameras and laptops are equipped with card readers, and microSD cards used in smartphones and other pocket gadgets can be used in SD slots using simple adapters. Thanks to the
card reader, you can, for example, easily view materials captured on a camera or smartphone camera, copy music and movies from a laptop to a media centre, and even perform some special tasks, such as updating the player's firmware. In video capture devices, the built-in card reader allows user to add the drive to the list of computer disks.
LAN
LAN — connector for wired connection to the Internet and/or local area network using an Ethernet cable. A wired connection is not as convenient as Wi-Fi (see "Multimedia"), but it is considered more reliable and provides faster data transfer speeds. And the speed indicators depend on the device and can be 100 Mbps and 1 Gbps.
Drive slot
The presence "under the hood" of the device slot for installing an internal drive.
This feature is found both in models that already have their own drive, and in devices without built-in storage. Anyway,
the drive slot allows the owner to equip the media centre with built-in memory at his discretion, independently choosing the volume and other characteristics of such memory. Such an opportunity will be especially useful for those who would like to keep an extensive collection of films and other content directly in the device’s memory: choosing a model with the desired set of characteristics and purchasing a hard drive of the required capacity for it is easier than looking for a device that initially has both certain operating parameters and sufficient amount of built-in storage.
Note that the slots for the drive can have a different form factor and connection interface; this point should be clarified by the characteristics. However, with the search for hardware for such slots nowadays, usually, there are no problems.