These are the numbers that we would typically use on a day-to-day basis this is know as a
base-10 numbering system (We use a base-10 number system because when we started counting we use our hands which have 10 fingers)

Numbers we use in Decimal
0,1,2,3,4,5,6,7,8,9

Because there are 10 unique digits it is called a base-10 numbering system

Where in the Binary numeral system we use powers of 2 in decimal we use powers of 10 so
1, 10, 100, 1000, 10000 …

10 in different numbering systems
Decimal = 10
Binary = 0b1010
octal = 0o12
Hexadecimal = 0xA (or 0xa)