What is the difference between “any” or ”every”?

Solution 1:

Any is polysemous.

AHD:

any [quantifier]

1. One, some, every, or all without specification

choosing examples:

Are there any messages for me?

[meaning one or some]

Any child would love that.

[meaning every]

But

The system is deterministic if any two runs produce the same result.

is itself an example of a scope ambiguity:

Do we mean

The system is deterministic if there have been / are any two runs producing the same result.

or

The system is deterministic if all the possible selected pairs of runs produce the same result. (when it would be clearer just to say The system is deterministic if all runs produce the same result).

Perhaps a clearer illustration of this ambiguity is:

If any child can afford to come [we'll ask their parents to contribute to the new library].

If any child can afford to come [we'll need two coaches].

Solution 2:

Any thing means considering one of the things.

Every thing is considering all the things individually.

Mostly they can be used interchangeably but "any" usually means negatively. For example:

-- You can use every thing that you have.

-- You cannot use any thing!

Solution 3:

Any stands for any random pick, while every stands for every single.

Grammatically, these are different phrases, but, if we think carefully, they mean the same thing. So, you can use both equivalently. If they were not, there would exist a counterexample. There must be one since there are people in the question’s comments who oppose my claim. But they fail to provide the counterexample needed to support that position.