int x
defines a variable named x.
x = 5
assigns 5 to x.
You can use direct initialization like so:
int width(5);
which saves copying complex types from the right to the left.
int width { 5 };
int height = { 6 };
You'll want to always initialize your variables on creation, and use uniform initialization.
#include <iostream> // for std::cout and std::cin
int main() {
std::cout << "Enter a number: "; // ask user for a number
int x{ }; // define variable x to hold user input (and zero-initialize it)
std::cin >> x; // get number from keyboard and store it in variable x
std::cout << "You entered " << x << '\n';
return 0;
}