Merge pull request #917 from rpjday/references

More minor tweaks and rewording for "Git References" section

book/10-git-internals/sections/refs.asc

@@ -1,10 +1,10 @@
 [[_git_refs]]
 === Git References
 
-You can run something like `git log 1a410e` to look through your whole history, but you still have to remember that `1a410e` is the last commit in order to walk that history to find all those objects.
-You need a file in which you can store the SHA-1 value under a simple name so you can use that pointer rather than the raw SHA-1 value.
+If you were interested in seeing the history of your repository reachable from commit, say, `1a410e`, you could run something like `git log 1a410e` to display that history, but you would still have to remember that `1a410e` is the commit you want to use as the starting point for that history.
+Instead, it would be easier if you had a file in which you could store that SHA-1 value under a simple name so you could use that simple name rather than the raw SHA-1 value.
 
-In Git, these are called ``references'' or ``refs''; you can find the files that contain the SHA-1 values in the `.git/refs` directory.
+In Git, these simple names are called ``references'' or ``refs''; you can find the files that contain those SHA-1 values in the `.git/refs` directory.
 In the current project, this directory contains no files, but it does contain a simple structure:
 
 [source,console]
@@ -33,8 +33,7 @@ cac0cab538b970a37ea1e769cbbde608743bc96d second commit
 fdf4fc3344e67ab068f836878b6c4951e3b15f3d first commit
 ----
 
-You aren't encouraged to directly edit the reference files.
-Git provides a safer command to do this if you want to update a reference called `update-ref`:
+You aren't encouraged to directly edit the reference files; instead, Git provides the safer command `git update-ref` to do this if you want to update a reference:
 
 [source,console]
 ----
@@ -91,7 +90,7 @@ ref: refs/heads/test
 
 When you run `git commit`, it creates the commit object, specifying the parent of that commit object to be whatever SHA-1 value the reference in HEAD points to.
 
-You can also manually edit this file, but again a safer command exists to do so: `symbolic-ref`.
+You can also manually edit this file, but again a safer command exists to do so: `git symbolic-ref`.
 You can read the value of your HEAD via this command:
 
 [source,console]
@@ -100,7 +99,7 @@ $ git symbolic-ref HEAD
 refs/heads/master
 ----
 
-You can also set the value of HEAD:
+You can also set the value of HEAD using the same command:
 
 [source,console]
 ----
@@ -119,10 +118,10 @@ fatal: Refusing to point HEAD outside of refs/
 
 ==== Tags
 
-We just finished discussing Git's three main object types, but there is a fourth.
-The _tag_ object is very much like a commit object – it contains a tagger, a date, a message, and a pointer.
+We just finished discussing Git's three main object types (_blobs_, _trees_ and _commits_), but there is a fourth.
+The _tag_ object is very much like a commit object -- it contains a tagger, a date, a message, and a pointer.
 The main difference is that a tag object generally points to a commit rather than a tree.
-It's like a branch reference, but it never moves – it always points to the same commit but gives it a friendlier name.
+It's like a branch reference, but it never moves -- it always points to the same commit but gives it a friendlier name.
 
 As discussed in <<_git_basics_chapter>>, there are two types of tags: annotated and lightweight.
 You can make a lightweight tag by running something like this:
@@ -132,10 +131,10 @@ You can make a lightweight tag by running something like this:
 $ git update-ref refs/tags/v1.0 cac0cab538b970a37ea1e769cbbde608743bc96d
 ----
 
-That is all a lightweight tag is – a reference that never moves.
+That is all a lightweight tag is -- a reference that never moves.
 An annotated tag is more complex, however.
 If you create an annotated tag, Git creates a tag object and then writes a reference to point to it rather than directly to the commit.
-You can see this by creating an annotated tag (`-a` specifies that it's an annotated tag):
+You can see this by creating an annotated tag (using the `-a` option):
 
 [source,console]
 ----
@@ -150,7 +149,7 @@ $ cat .git/refs/tags/v1.1
 9585191f37f7b0fb9444f35a9bf50de191beadc2
 ----
 
-Now, run the `cat-file` command on that SHA-1 value:
+Now, run `git cat-file -p` on that SHA-1 value:
 
 [source,console]
 ----
@@ -173,7 +172,7 @@ You can view the public key by running this in a clone of the Git repository:
 $ git cat-file blob junio-gpg-pub
 ----
 
-The Linux kernel repository also has a non-commit-pointing tag object – the first tag created points to the initial tree of the import of the source code.
+The Linux kernel repository also has a non-commit-pointing tag object -- the first tag created points to the initial tree of the import of the source code.
 
 ==== Remotes