What is the point of compressing video from camcorders?

You seem to be mixing 3 different topics. We have broken them down for you. 1. Compression: Regardless of what data you are compressing, compression is always for saving storage space but it can also provide other advantages. In media, compression helps provide data in a universal format. Because smaller files are easier and faster to send than larger ones, compression can also increase speed. Your cable modem uses data compression to increase the speed of data flow between your home and the cable company, and it does it on several channels at once allowing you to enjoy more broadband services than ever before. (Compression can also be used to "encrypt" data for security purposes too). Currently, compression can decrease your storage space to around 1/4 of the original size. This can also speed up communications, but the compression can also slow down playback and editing if the system handling the compressed data does not have the proper amount of RAM, processor speed, bus speed, and bandwidth (i.e.: 64bit instead of 32bit or dual data rate instead of single). MPEG-2 is the most common video compression codec. It has been used for over a decade, and it is used in various forms in almost every video device. It is the basis of standard DVDs, digital satellite television, and HDV recording. MPEG-2 is variable compression because it only compresses similar areas from frame to frame, and this changes from video segment to video segment. For example: if you are filming someone spinning on one point in the middle of the frame, only the middle of the video changes from frame to frame while the areas on either side and above the person remain the same. Since the area around the individual is always the same, that part of the video is compressed and reused from frame to frame. The part of the video with the dancing person is new, uncompressed data in each frame. MPEG-2 doesn't compress everything in every frame, but it is good enough to squeeze HD video onto the older standard definition miniDV tapes and send HD video through the DirecTV and Dish Network system. The great advantage of MPEG-2 is that almost every system since 2007 can handle it without any degradation of video or loss of speed. MP4 is a new version of compression from the same creators of MPEG-2. MP4 was developed to take advantage of today's quick broadband system and dual/quad core computer systems. MP4 compresses everything in each individual frame. This makes video files 2-3 times smaller than MPEG-2 and allows for quicker, universal distribution. The only problem with MP4 is that most computers systems made before 2007 can't uncompress the video as quickly as the audio. Plus the uncompressed video files may bee too large for the computer or display system to handle. This is the most common cause of video which lags behind the audio or freezes altogether. 2. Storage and Media When you talk about DVD, flash memory, hard disc drive (HDD), and tape (miniDV, HDV, Digital8, Hi-8, 8mm), you are talking about media and storage formats - not compression. All of these different media types have different pros and cons http://motionpicturecentral.com/filmmaking/camcorders/camcorder-formats/ , and they use different compression formats as well. MiniDV, HDV, and DVDs all use MPEG-2 compression for storing video data, but they each use it in a different way. HDD and flash memory most commonly use H.264 in MP4, but they might also use MOD/TOD or another form of MPEG-2 called AVCHD. Compression can matter a lot when sharing is a concern. When you upload a video to YouTube, it is converted from your compression format to the Flash format. Flash has the great advantage of good compression without loss of speed on almost every computer regardless of age, capability, and internet speed (but you need to download the entire video before playing on older, less capable systems). If Youtube did not use a universal codec such as Flash, everyone would need a certain type of computer system with a specific minimum of display resolution to view whatever compression YouTube chose. A good example of this is issue Vimeo. If you don't have a computer and display system made in 2007 or later, you probably can't view the HD videos stored there. 3. Camcorder When you talk about finding the right camcorder for your needs, you need to identify your needs. What conditions do you need to film in? What do you need to camera to do? What situations will you face the most with your camcorder? http://motionpicturecentral.com/filmmaking/camcorders/choosing-a-camcorder/ * You can use an HDV, miniDV, or Digital 8 camcorder with your existing computer. These cameras were designed to connect with your computer and use the existing video editing software that came with your computer (Windows Movie Maker or iMovie). http://motionpicturecentral.com/editing/video-capture/how-to-connect-an-hdv-minidv-or-digital8-camcorder-to-a-computer/