 The angle brackets surrounding codice_184 indicate that codice_184 is located using a search strategy that prefers headers provided with the compiler to other headers having the same name, as opposed to double quotes which typically include local or project-specific header files.The next line indicates that a function named codice_189 is being defined.The codice_189 function serves a special purpose in C programs; the run-time environment calls the codice_189 function to begin program execution.