Add note on submodule "mental model"

1 files changed, 8 insertions, 0 deletions

diff --git a/cheatsheet.txt b/cheatsheet.txt
index 92bc1e5..bcb5e4c 100644
--- a/cheatsheet.txt
+++ b/cheatsheet.txt
@@ -179,6 +179,14 @@ History Cleanup
 
 Submodules
 
+  Think of a submodule as a pointer to a specific commit (as opposed
+  to something "latest") in another project. Moving this pointer to
+  another commit is an explicit change to the containing project that
+  we must perform and then commit. In many situations this pointer
+  will be "dangling", that is, the actual files corresponding to the
+  commit won't be checked out unless we run an extra command or pass
+  an extra option to make git do so.
+
   git config --global status.submoduleSummary true
   git config --global diff.submodule log