I know what tracking and kerning are I just want to know what the title for the space between words are.
It is simply called Word spacing.
Word spacing in typography refers to the size of the space between words. It should be distinguished from letter-spacing (the spacing between the letters within each word) and sentence spacing (the spacing between sentences). Typographers may modify the spacing of letters or words in a body of type to aid readability and copy fit, or for aesthetic effect. In web browsers and standardized digital typography the word spacing is controlled by the CSS1 word-spacing property.
Related, if not a duplicate: Is there a term for adjusting the spacing between WORDS for a font (not letters)?