All digital data are stores as binary. Eg Words, Cameras, Monitors...
When converting binary into decimals or reverse the left side is the most significant bit and the right side is the least significant bit.
8 bits = 1byte
BCD is when we code each part of the data by using a nibble.
By using Sign Magnitude method we loose a bit meaning the biggest number we can store is 127.
We assume that the MSB is a negative and the rest of the bit is positive adding to the negative number.
Three way of coding
EBCDIC is dead, stores data on a magnetic tape. cannot store keyboards characters.
ASCII every keyboard character is given a corresponding binary code. every letter is given a binary number.
UNICODE uses 2 bytes it is replacing ASCII it is used to cover more languages in the world, it is more important in the internet as it can store more languages.