diff --git a/lib/picopackage/source_file.rb b/lib/picopackage/package.rb
similarity index 100%
rename from lib/picopackage/source_file.rb
rename to lib/picopackage/package.rb
diff --git a/notes.md b/notes.md
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--- /dev/null
+++ b/notes.md
@@ -0,0 +1,25 @@
+## Package Installation Flow
+
+1. **Fetch URL**
+   └─> Download content
+   └─> Build Package Instance (Metadata & Payload)
+   └─> Check local file status
+
+2. **Local File Check**
+   ├─> If file doesn't exist:
+   │   └─> Save file
+   │
+   └─> If file exists:
+       └─> Compare versions
+           ├─> If older/same:
+           │   └─> "Package already installed"
+           │
+           └─> If newer:
+               └─> Check local modifications
+                   ├─> If modified:
+                   │   └─> "Local modifications detected"
+                   │   └─> "Use 'update <file_path>'"
+                   │
+                   └─> If unmodified:
+                       └─> "Update available"
+                       └─> "Use 'update <file_path> -f' to force update"