1. Code, which can be short for source code, is a term used to describe text that is written using the protocol of a particular language, such as C, Java, Perl, PHP, or other programming language by a computer programmer. Code can also be used in a less formal fashion to refer to text written for markup or styling languages like HTML and Cascading Style Sheets (CSS). For example, you may see people make reference to code in numerous languages, such as "C code", "PHP code", "HTML code", or "CSS code."
2. When writing in HTML, the <code> tag is used to designate that a section of text is computer code.