A: 4K â also known as UHD (more on this in the next answer!) â is a picture technology that quadruples the number of pixels found in a full HD picture. These pixels are usually arranged in a 3,840 x 2,160 configuration, compared with the 1920x1080 you get in a full HD TV.
Files with the .7z extension are very similar to Zip files. These files are compressed archive files, usually created by the 7-Zip file archive utility. 7Z files can make it easier to send files and folders over email and the Web.
Gz is a compressed file extension. It stands for GNU Zip, after the GNU operating system. It was adopted by the GNU project, and is a popular compression format on the Internet. You can unzip .gz files in Windows XP, Vista, 7, and Mac OS X by using unzipping software that supports the file extension.