Both Term Frequency (TF) and Inverse Document Frequency (IDF) are measures of the frequency of a particular keyword use on a webpage. The measure is calculated by comparing the rate on a given webpage with the frequency of that keyword’s use on other similar webpages.
SEO best practice dictates that TF and IDF should not be too high, as this is read by Google’s crawler bot as something akin to spam or trying to trick the bot into a higher rank on search engine results pages (SERP), which normally backfires.
