What is the difference between compression card and DVR, DVR and NVR

When you say compression card, you mean **capture card! The capture card is to compress and collect the best signal into the computer, the storage is in the computer, DVR is another name for the DVR, it is mainly the signal compression, storage in the DVR in the hard disk, playback, etc. are realized in DVR, DVR is equivalent to a collection of N multiple capture cards and computers, but the performance is more stable, suitable for 24 hours always open!

It is a set of computer systems for image storage processing, with the function of long-term video recording, recording, remote monitoring and control of image voice, DVR integrates five functions such as video recorder, screen splitter, PTZ lens control, alarm control, network transmission, etc., with a device can replace the function of a large number of equipment in the analog monitoring system, and gradually occupies an advantage in the first place.

The network DVR records through your personal needs, and uses the serial port (most) hard disk to store the video. And in the case of connecting to the network, you can achieve the purpose of remote monitoring by registering a dynamic domain name.

DVR Chinese called network hard disk DVR, can put hard disk, can store the analog camera connected to the DVR, note: is an analog camera.

NVR is more similar to a disk array, which provides network storage space for IPC or DVS, that is, it stores the encoded and networked stream.

The main differences are as follows:

1. The way of access is different, one is digital and the other is analog.

2. The storage capacity is different, DVR can install up to 8 SATA hard disks, and then use the ESATA interface to expand 1 hard disk, up to 9 hard disks; Due to the differences of various manufacturers, some have 16 disks, some have 24 disks, and even 48 disks. In fact, at this stage, most of the NVR is the embedded monitoring software platform in the storage of the x86 architecture, and the general disk array supports expansion, and some manufacturers weigh the expansion cabinet in order to facilitate it, which also improves the **. (The x86 architecture storage expansion capacity is not high, and the stability is not strong, in general, in order to increase the expansion capacity, the CPU and cache need to be increased, so the cost will also increase.)

3. Storage security, DVR information storage is progressive storage, when a hard disk has a bad sector, the device will basically blue screen or crash, while NVR is based on disk array architecture, RAID protection mechanism, so the security of information storage is much higher than DVR.

The DVR is connected to the analog front-end (camera), which will encode the access signal;

NVR access to the front-end of the network does not encode the signal because the encoding process is already done on the webcam side.

To put it bluntly, NDR is a decoding device, a recording device, and DVI is an encoding device.

NVR is a digital-analog dual-input video recorder.

DVR is a video recorder with analog signal input.

It's definitely the first one, just look at it.