Changes

:'''Lexical analysis''': convert the source code into a sequence of tokens, such as variable names, keywords, numbers, and special symbols such as '+'.

:'''Lexical analysis''': convert the source code into a sequence of tokens, such as variable names, keywords, numbers, and special symbols such as '+'.

:'''Syntax analysis''' or '''parsing''': arrange the tokens into a parse tree or syntax tree which represents the structure of the program.

:'''Syntax analysis''' or '''parsing''': arrange the tokens into a parse tree or syntax tree which represents the structure of the program; check that the structure is valid.

:'''Semantic analysis''': annotate the parse tree with semantic actions, and perform various consistency checks; a symbol table is used to keep track of names declared by the programmer.

:'''Semantic analysis''': annotate the parse tree with semantic actions, and perform various consistency checks; a symbol table is used to keep track of names declared by the programmer.