An h-index h indicates that a researcher or journal has published h articles that have been cited h or more times.
Though it was originally developed as a measure of the influence of a single scholar, the h-index can also be applied to a periodical.
For more information, see the H-index for authors page
Google Scholar now tracks journal h-index based on citations from all publications that are indexed in Google Scholar. Google Scholar reports the "h5-index"; that is, the h-index calculated using the most recent five years of a journal's publication history. Users can search for metrics on a specific title or view the top-rated journals in a language or subject area.
To find the h-index:
Google Scholar generally finds more citing articles than Web of Science. Therefore, its h-indexes are usually higher. Different journals should not be compared unless the same source is used to generate the data for both.