Key difference: The main difference between ‘inter-’ and ‘intra-’ is that ‘inter-’ is used to denote in between, while ‘intra-’ denotes that it is inside or internal.
‘Inter-’ and ‘intra-’ are two prefixes commonly used in the English language. For example: international, intercollegiate, interdepartmental, intradepartmental, interdivisional, intra-divisional, etc. While, at first they may seem similar, they actually have two very different meanings.
Dictionary.com defines ‘inter-’ as “a prefix occurring in loanwords from Latin, where it meant “between,” “among,” “in the midst of,” “mutually,” “reciprocally,” “together,” “during” (intercept; interest); on this model, used in the formation of compound words (intercom; interdepartmental).” While, ‘intra-’ is defined as “a prefix meaning “within,” used in the formation of compound words: intramural.”
The main difference between ‘inter-’ and ‘intra-’ is that ‘inter-’ is used to denote in between, for example: international – between nations or countries; interdivisional – between two or more divisions (usually sports); interdepartmental – between two or more departments; inter-caste – between two caste; interschool – between two or more schools; inter-university – between two or more universities; intercollegiate – between two or more colleges; intermediate – in between the mediate or middle level; interstate – between states; inter-group – between two or more groups; internet – worldwide network; etc.
‘Intra-’, on the other hand, denotes that it is inside or internal. For example: intradepartmental – inside a department; intra-divisional – inside a division; intra-company – within the company; intracranial – inside the cranium or skull; intra-school – within the school; intra-group – within the group; intranet – network within a location such as house, work place; etc.