-#include <sys/types.h> /* predefined types */
-#include <unistd.h> /* include unix standard library */
-#include <arpa/inet.h> /* IP addresses conversion utiliites */
-#include <sys/socket.h> /* socket library */
-#include <stdio.h> /* include standard I/O library */
-#include <time.h>
+#include <sys/types.h> /* primitive system data types */
+#include <unistd.h> /* unix standard library */
+#include <arpa/inet.h> /* IP addresses conversion utilities */
+#include <sys/socket.h> /* socket constants, types and functions */
+#include <stdio.h> /* standard I/O library */
+#include <time.h> /* date and time constants, types and functions */