The expression $4C4$ represents a combination, which calculates how many ways you can choose 4 objects from a set of 4. The formula for combinations is:

$nCk = \frac{n!}{k!(n-k)!}$

In this case, $n = 4$ and $k = 4$, so:

$4C4 = \frac{4!}{4!(4-4)!} = \frac{4!}{4! \cdot 0!}$

Since $0! = 1$, we have:

$4C4 = \frac{4!}{4! \cdot 1} = \frac{4!}{4!} = 1$

So, $4C4 = 1$.

Would you like more details or have any questions about combinations?

Here are some related questions:

1. What is the formula for permutations, and how does it differ from combinations?
2. How do you calculate $5C3$?
3. What is the value of $6C2$?
4. Can you explain the difference between combinations and arrangements?
5. How can combinations be used in probability problems?

Tip: Combinations are used when the order of selection doesn't matter, while permutations are used when the order does matter.