diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7ba0217..0039f16 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,7 +25,7 @@
 
 ## 0.1.1
 
-- Use [MessagePack](https://github.com/msgpack/msgpack-ruby) for semaphore serialization.
+- Use [MessagePack](https://github.com/msgpack/msgpack-ruby) for lock serialization.
 
 ## 0.1.0
 
diff --git a/README.md b/README.md
index d73d8c1..58d8781 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,8 @@
 # Suo [![Build Status](https://travis-ci.org/nickelser/suo.svg?branch=master)](https://travis-ci.org/nickelser/suo) [![Code Climate](https://codeclimate.com/github/nickelser/suo/badges/gpa.svg)](https://codeclimate.com/github/nickelser/suo) [![Test Coverage](https://codeclimate.com/github/nickelser/suo/badges/coverage.svg)](https://codeclimate.com/github/nickelser/suo) [![Gem Version](https://badge.fury.io/rb/suo.svg)](http://badge.fury.io/rb/suo)
 
-:lock: Distributed semaphores using Memcached or Redis in Ruby.
+:lock: Distributed locks using Memcached or Redis in Ruby.
 
-Suo provides a very performant distributed lock solution using Compare-And-Set (`CAS`) commands in Memcached, and `WATCH/MULTI` in Redis.
+Suo provides a very performant distributed lock solution using Compare-And-Set (`CAS`) commands in Memcached, and `WATCH/MULTI` in Redis. It allows locking both single exclusion (a mutex - sharing one resource), and multiple resources.
 
 ## Installation
 
@@ -31,6 +31,7 @@ suo.lock("some_key") do
   @puppies.pet!
 end
 
+# The second argument to lock is the number of arguments (defaulting to one - a mutex)
 Thread.new { suo.lock("other_key", 2) { puts "One"; sleep 2 } }
 Thread.new { suo.lock("other_key", 2) { puts "Two"; sleep 2 } }
 Thread.new { suo.lock("other_key", 2) { puts "Three" } }
@@ -69,6 +70,10 @@ suo.lock("foo") do |lock|
 end
 ```
 
+## Semaphore
+
+With multiple resources, Suo acts like a semaphore, but is not strictly a semaphore according to the traditional definition, as the lock acquires ownership.
+
 ## TODO
  - more race condition tests
 
diff --git a/suo.gemspec b/suo.gemspec
index 36fa0cf..542de89 100644
--- a/suo.gemspec
+++ b/suo.gemspec
@@ -9,8 +9,8 @@ Gem::Specification.new do |spec|
   spec.authors       = ["Nick Elser"]
   spec.email         = ["nick.elser@gmail.com"]
 
-  spec.summary       = %q(Distributed semaphores using Memcached or Redis.)
-  spec.description   = %q(Distributed semaphores using Memcached or Redis.)
+  spec.summary       = %q(Distributed locks using Memcached or Redis.)
+  spec.description   = %q(Distributed locks using Memcached or Redis.)
   spec.homepage      = "https://github.com/nickelser/suo"
   spec.license       = "MIT"