Primes of the form 4n+1 are defined as primes that yield a remainder of 1 when divided by 4. The discussion centers on proving that there are infinitely many such primes, with suggestions to use proof by contradiction. Participants express confusion about the logic behind the question and clarify the definition of primes in this context. Examples of primes fitting this form include 5, 13, 17, and 29, demonstrating the concept. The conversation highlights the need for a rigorous proof to establish the infinitude of these primes.