The Kilobyte is a multiple of a byte unit, the term has historically been used to refer to 1024 bytes (although in some contexts it may also represent 1000 bytes). This difference is related to the fact that the measurement units in computing are based on base 2 multiples (because of the bit). But the term kilo used as a prefix in units of measurement usually means 1000. To address this discrepancy, in 2000, the IEEE (Institute of Electrical and Electronics Engineers) approved new units of measurement, in which the Kibibyte (KiB) would be 1024 bytes, whereas the kilobyte would represent 1000 bytes. However, these new units did not have a great reception by the digital community. A kilobyte represents (approximately) the amount of information needed to store this paragraph you just read.
The Byte is a digital information unit equivalent to eight bits. Each byte represents a single text character on a computer. A byte can represent a letter, a symbol, a number or a punctuation mark. The byte is used to specify the size or amount of memory or the storage capacity of a device. Some programming languages use the term byte to represent an integer-type variable, which takes up less space than other similar numeric variables. Something similar also occurs in the vast majority of databases. Because storage space is very important, sometimes when you want to store an integer, you should get an idea of the size of that number. For example, if we want to store the age of a person we will not need such large numbers as to save the balance of our bank account, which in some cases can reach several digits.