Many different computer languages are used to store data. Each languages has its strengths and weaknesses. Some are very efficient and can store vast amounts of data in a small amount of storage space. Others are not. If you want to know more about how a computer stores data, read the Computer Basics web page about Data Types & Languages. The computer industry has developed a variety of utility programs for recoding data to take up less storage space than it does in its normal data language. This process is called "compression". The process of converting compressed data back into its original language is called "decompression" (or "uncompression"). Collectively the pair of processes is referred to as "codex". Another related process involves combining many files (and/or folders) into a single file called an "archive". If we create an archive and then compress it, the resulting file is called a "compressed archive". Many people call compressed archives "zip files" (named after a popular codex utility named PKZIP.) The act of creating a compressed archive is often called "zipping" files or folders.
There are many codex/zipping utilities available. Windows includes one named simply "Compressed (zipped) Folders", but many computers also have third-party codex utilities installed, such as [PKZIP®], [StuffIt®], or [WinZip®]. Third party compression utilities often override the built-in Windows utility, but normally do not replace it entirely. You might find that a third party codex utility actually alters the choices that appear on contextual menus that appear when right-clicking items in Windows' Computer program. The procedures below are based on the codex utility built-in to Windows without any other third-party utility. Users might have to modify the steps if third party utilities such as WinZip is installed.
You should then notice a new file with an icon that looks similar to the standard yellow folder icon, but with a grey zipper running down the left side. Despite looking like a folder and perhaps containing many files and folders, it is actually treated by Windows as a single data file rather than a folder. So you will not normally see it displayed in the Navigation Pane (file hierarchy diagram in the left panel) of the Window's File Explorer program. This file should be significantly smaller than its combined source content. It will have the same name as the original file or folder in step 1 above, but can be changed like any other file. But be sure not to change or remove the .zip extension.
You should then notice a new file with an icon that looks similar to the standard yellow folder icon, but with a grey zipper running down the left side. Despite looking like a folder and perhaps containing many files and folders, it is actually treated by Windows as a single data file. So you will not normally see it displayed in the Navigation Pane (file hierarchy diagram in the left panel) of the Window's File Explorer program. This file should be significantly smaller than its combined source content. It will have the same name as the original file or folder in step 1 above, but can be changed like any other file. But be sure not to change or remove the .zip extension.
You should then see the file(s) or folder(s) listed in the Contents Pane (right-hand panel) in the Window's File Explorer program. If you have the Navigation Pane open in the left-hand panel in the File Explorer window, you will see the compressed archive listed in the file hierarchy (tree) diagram. You can copy and paste or drag and drop any files or folders to or from a compressed archive file.