epoll.7: Some minor clarifications at start of DESCRIPTION

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man7/epoll.7

@@ -24,21 +24,24 @@ epoll \- I/O event notification facility
 .SH SYNOPSIS
 .B #include <sys/epoll.h>
 .SH DESCRIPTION
+The
 .B epoll
-is a variant of
-.BR poll (2)
-that can be used either as an edge-triggered or a level-triggered
+API performs a similar task to
+.BR poll (2):
+monitoring multiple file descriptors to see if I/O is possible on any of them.
+The
+.B epoll
+API can be used either as an edge-triggered or a level-triggered
 interface and scales well to large numbers of watched file descriptors.
 The following system calls are provided to
 create and manage an
 .B epoll
 instance:
 .IP * 3
-An
+.BR epoll_create (2)
+creates an
 .B epoll
-instance created by
-.BR epoll_create (2),
-which returns a file descriptor referring to the epoll instance.
+instance and returns a file descriptor referring to that instance.
 (The more recent
 .BR epoll_create1 (2)
 extends the functionality of
@@ -52,8 +55,9 @@ instance is sometimes called an
 .I epoll
 set.
 .IP *
-Finally, the actual wait is started by
-.BR epoll_wait (2).
+.BR epoll_wait (2)
+waits for I/O events,
+blocking the calling thread if no events are currently available.
 .SS Level-Triggered and Edge-Triggered
 The
 .B epoll