1. Integer, usually called integer without decimal point, such as 123, 45678, etc. Integers in C language include not only decimal integer data, but also octal and hexadecimal forms, such as 034 as octal number and 0x 12e4 as hexadecimal number. "Plastic surgery" is the difference in writing, and generally no technical terms are used.

2. Real type, commonly known as real number, also known as floating point number, is a number with decimal point. Real numbers are divided into single-precision numbers and double-precision numbers, indicating that the significant digits of data are different. Generally, the single precision number is 7 significant digits, and the double precision number is 15 significant digits. Representation can be divided into decimal and exponential representations, such as 123.456 as decimal and 1.23456e2 as exponential representation. Decimals and exponents are expressed in floating-point form in computers, which means that decimal points can be moved. For example, 123.456 can be expressed as 1.23456e2 and 12.3456e 1, so real numbers are also called floating-point numbers.