diff --git a/episodes/03-create.md b/episodes/03-create.md
index fcfdae144..6b5517b45 100644
--- a/episodes/03-create.md
+++ b/episodes/03-create.md
@@ -93,6 +93,17 @@ The `-R` option to the `ls` command will list all nested subdirectories within a
 Let's use `ls -FR` to recursively list the new directory hierarchy we just created in the
 `project` directory:
 
+The `-R` option to the `ls` command will list all nested subdirectories within a directory.
+`R` in `-R` stands for "Recursive" which refers to the idea that the output of a process
+becomes the input of another iteration of that same process.
+So in this case, `ls -R` lists the contents of a directory, and for every directory
+it finds, it lists the contents of that directory,
+and for every directory inside those subdirectories,
+it lists the contents, and so on.
+
+Let's use `ls -FR` to recursively list the new directory hierarchy we just created in the
+`project` directory:
+
 ```bash
 $ ls -FR ../project
 ```
@@ -477,9 +488,12 @@ $ ls quotes.txt thesis/quotations.txt
 quotes.txt   thesis/quotations.txt
 ```
 
-We can also copy a directory and all its contents by using the
-[recursive](https://en.wikipedia.org/wiki/Recursion) option `-r`,
-e.g. to back up a directory:
+Just like the recursive (`-R`) option for `ls`,
+the `-r` option for `cp`
+applies the command not just to the specifed directory,
+but to all its contents.
+
+As an example, we can use this to back up a directory:
 
 ```bash
 $ cp -r thesis thesis_backup
diff --git a/episodes/07-find.md b/episodes/07-find.md
index 984d53f77..cf4496b56 100644
--- a/episodes/07-find.md
+++ b/episodes/07-find.md
@@ -192,9 +192,11 @@ $ grep -n -w -v "the" haiku.txt
 ```
 
 If we use the `-r` (recursive) option,
-`grep` can search for a pattern recursively through a set of files in subdirectories.
+`grep` can search for a pattern through all the files in
+in a directory and its subdirectories subdirectories.
 
-Let's search recursively for `Yesterday` in the `shell-lesson-data/exercise-data/writing` directory:
+Let's search "recursively" for `Yesterday`
+in the `shell-lesson-data/exercise-data/writing` directory:
 
 ```bash
 $ grep -r Yesterday .
@@ -337,7 +339,8 @@ $1.txt
 cut -d , -f 1,3
 ```
 
-Hint: use `man grep` to look for how to grep text recursively in a directory
+Hint: use `man grep` to remind ourselves how to find text in a directory
+recursively (meaning include all subdirectories in the search)
 and `man cut` to select more than one field in a line.
 
 An example of such a file is provided in
diff --git a/learners/reference.md b/learners/reference.md
index 484ecaa6b..699384172 100644
--- a/learners/reference.md
+++ b/learners/reference.md
@@ -160,6 +160,12 @@ so that the shell will not try to expand the `*` wildcard.
 :   (REPL): A [command-line interface](#command-line-interface) that reads a command from the user,
 executes it, prints the result, and waits for another command.
 
+[recursive]{#recursive}
+:   A recursive precudure is one where one step of the procedure is to apply the procedure itself
+(usually to a different input).
+In the context of shell, it often refers to applying a command to a directory and to all directories
+contained within that directory.
+
 [redirect]{#redirect}
 :   To send a command's output to a file rather than to the screen or another command,
 or equivalently to read a command's input from a file.