In some cases, URLs are used to locate resources that contain pointers to other resources. In some cases, those pointers are represented as relative links where the expression of the location of the second resource is in terms of "in the same place as this one except with the following relative path". Relative links are not described in this document. However, the use of relative links depends on the original URL containing a hierarchical structure against which the relative link is based.
Some URL schemes (such as the ftp, http, and file schemes) contain names that can be considered hierarchical; the components of the hierarchy are separated by "/".