What are the PrimePages?

Webster's New Collegiate Dictionary defines prime as follows.

prime \'prīm\ n [ME, fr. MF, fem. of prin first, L primus; akin to L prior] 1 : first in time : ORIGINAL 2 a : having no factor except itself and one <3 is a ~ number> b : having no common factor except one <12 and 25 are relatively ~> 3 a : first in rank, authority or significance : PRINCIPALb : having the highest quality or value <~ television time>

Each of Webster's definitions apply, but the most operative is 2a: An integer greater than one is prime if its only positive divisors are itself and one.  For example 15 is not prime because it has other divisors, namely the primes 3 and 5.  These pages presents lists of large primes and key research about them.