A tar is a linked list of file paths and contents, it cannot be indexed to a particular file. A compressed tar has to first be decompressed and then the chain o

A tar is a linked list of file paths and contents, it cannot be indexed to a particular file. A compressed tar has to first be decompressed and then the chain of links traversed. Accessing a file in compressed tar is o(n) with where the file is placed within the compressed tar stream. It isn't that it is possible, it is that is horribly inefficient. Zips on other hand unify storage and compression such that one has random access to particular file, hence most modern file formats are zips with xml or json inside.