As it may be clear from the context, the archiver is used for any program that allows you to compress or archive files and folders. Such and best archiver for mac is generally used to save space on the system by compressing and reducing the size of the file. The archiver in no way affects the integrity and quality of the files and folder within.
Different archiver tools come with different features like encryption options, folder sharing, etc. If you are looking for one such tool, check the above list of best zip software for mac for ease.