You now understand that all number systems work the same way: each position is a power of the base, and you sum those powers to get the value.
Binary (base-2) is how computers represent data. Hex (base-16) compresses binary for readability. Powers of 2 appear everywhere in algorithm analysis. Bitwise operations are fast, low-level tools. Two's complement handles negative numbers elegantly.
These concepts underlie memory addressing, data structures like bitmasks, and optimization techniques. When you see a hex address or a binary flag in production code, you will know exactly what it means.