How should I understand the definition of computational problem?A computational problem is a mathematical object representing a  collection of questions that computers might be able to solve. For  example, the problem of factoringGiven a positive integer n, find a nontrivial prime factor of n.What is the mathematical object in the example above? Quoting Wikipedia again:Commonly encountered mathematical objects include numbers,  permutations, partitions, matrices, sets, functions, and relations.So how can you 'represent' a collection of questions with numbers or permutations, matrices etc.? What is meant here is probably the following collection of sentences:'find a nontrivial prime factor of 1', 'find a nontrivial prime factor of 2' and so on...But the thing is - these sentences are not mathematical objects.A little further in the article it reads:A computational problem can be viewed as an infinite collection of  instances together with a solution for every instance.which makes perfect sense, but I don't quite see the relationship with the first definition.
Computational problem - definition
terminology;computation models