Hex is a sixteen-digit shorthand for bits. Each hex digit is exactly four bits, so a byte is two digits, and reading hex is far easier than reading a long row of ones.
About 2 min of reading
Read and write hex.
Print what ff means.
Before you run it, say out loud what it will print. Then open the answer.
Show the bits of one hex digit.
Before you run it, say out loud what it will print. Then open the answer.
Print bytes as hex pairs.
Before you run it, say out loud what it will print. Then open the answer.
Turn hex back into bytes.
Before you run it, say out loud what it will print. Then open the answer.
Read the first example one line at a time. A line that prints shows what appears on screen; the rest set things up quietly.
The bits in memory do not change when you write them as hex. Hex is for humans, and it groups bits where bytes begin.
Colors, file signatures, hashes, and byte dumps are all hex. Learning to read pairs of digits covers all of them.
print(0xff)The digit f is fifteen, so ff is 255. Hex is a shorter way to write the same bits, not a different value.
print(bin(0xf))
print(bin(0x1))One hex digit is four bits. That is why a byte is always two hex digits, side by side.
print(b"\x00\x01\xff".hex())A row of bytes prints as pairs of hex digits. That is what a hex editor shows you.
print(bytes.fromhex("6f776c"))Hex text turns back into bytes. The pairs are read two at a time, left to right.
print(int("ff", 16))A color is three bytes written as six hex digits. The same rule reads a color and reads a file.
print(int("ff", 16))
print(int("10", 16))Reading text as base sixteen gives 255 and 16. The base says how much each position is worth.
print(0b1111 == 0xf)Hex groups bits by four, which lines up with bytes. Octal groups by three and does not, so hex won.
print("48656c6c6f".hex())Hex pairs are bytes. Two hex digits per byte is the rhythm that makes a dump readable.
Each one is defined here on this site. Open the entry for the full definition and the other words it points at.