diff --git a/api/contributions.php b/api/contributions.php
index 55ac14b..7e23ebb 100644
--- a/api/contributions.php
+++ b/api/contributions.php
@@ -64,7 +64,7 @@ function handle_read($input) {
 
     $municipality_id = $input['municipality_id'];
 
-    // Builds SQL Query
+    // Builds SQL Query with Placeholders for prepared Statement
     $sql = "SELECT *, ST_AsGeoJSON(geom) AS geojson 
             FROM contributions 
             WHERE municipality_id = :mid AND status = 'approved'";
@@ -79,8 +79,10 @@ function handle_read($input) {
     $sql .= " ORDER BY created_at DESC";
 
     try {
+        // Prepared Statement to prevent SQL Injection
         $stmt = $pdo->prepare($sql);
         $stmt->execute($params);
+        // Fetches Results as PHP-Array
         $rows = $stmt->fetchAll();
     } catch (PDOException $e) {
         error_response('Database Error: ' . $e->getMessage(), 500);
@@ -113,14 +115,14 @@ function handle_read($input) {
 
 
 // ---------------------------------------------------------------------
-// CREATE — Insert a new Contribution
+// CREATE: Inserts new Contributions
 // Required: municipality_id, geom, geom_type, category, title, author_name
 // Optional: description
 // ---------------------------------------------------------------------
 function handle_create($input) {
     $pdo = get_db();
 
-    // Validate Input
+    // Validates Input
     $missing = validate_required($input, [
         'municipality_id', 'geom', 'geom_type', 'category', 'title', 'author_name'
     ]);
@@ -128,18 +130,19 @@ function handle_create($input) {
         error_response('Missing Fields: ' . implode(', ', $missing));
     }
 
-    // Validate Geometry Type
+    // Validates Geometry Type
     $valid_geom_types = ['point', 'line', 'polygon'];
     if (!in_array($input['geom_type'], $valid_geom_types)) {
-        error_response('Invalid geom_type. Must be: ' . implode(', ', $valid_geom_types));
+        error_response('Invalid Geometry Type. Must be: ' . implode(', ', $valid_geom_types));
     }
 
-    // Validate GeoJSON
+    // Validates GeoJSON
     $geojson = json_decode($input['geom']);
     if (!$geojson || !isset($geojson->type)) {
-        error_response('Invalid GeoJSON in geom Field.');
+        error_response('Invalid GeoJSON in Geometry Field.');
     }
 
+    // Prepared SQL Statement
     try {
         $stmt = $pdo->prepare("
             INSERT INTO contributions 
@@ -171,15 +174,15 @@ function handle_create($input) {
 
 
 // ---------------------------------------------------------------------
-// UPDATE — Update an existing Contribution
+// UPDATE: Updates existing Contributions
 // Required: contribution_id
 // Optional: category, title, description, status
-// Only provided Fields are updated — others remain unchanged.
+// Provided Fields are updated. Others remain unchanged.
 // ---------------------------------------------------------------------
 function handle_update($input) {
     $pdo = get_db();
 
-    // Validate Input
+    // Validates Input
     $missing = validate_required($input, ['contribution_id']);
     if (!empty($missing)) {
         error_response('Missing Fields: ' . implode(', ', $missing));
@@ -187,14 +190,14 @@ function handle_update($input) {
 
     $contribution_id = $input['contribution_id'];
 
-    // Check if Contribution exists
+    // Checks if Contribution exists
     $stmt = $pdo->prepare("SELECT contribution_id FROM contributions WHERE contribution_id = :id");
     $stmt->execute([':id' => $contribution_id]);
     if (!$stmt->fetch()) {
         error_response('Contribution not found.', 404);
     }
 
-    // Build dynamic UPDATE Query — only update Fields that were sent
+    // Builds dynamic SQL Query to only update sent Fields
     $updatable_fields = ['category', 'title', 'description', 'status'];
     $set_clauses = [];
     $params = [':id' => $contribution_id];
@@ -210,16 +213,18 @@ function handle_update($input) {
         error_response('No Fields to update. Provide at least one of: ' . implode(', ', $updatable_fields));
     }
 
-    // Validate Status if provided
+    // Validates Status
     if (isset($params[':status'])) {
         $valid_statuses = ['pending', 'approved', 'rejected', 'in_progress', 'done'];
         if (!in_array($params[':status'], $valid_statuses)) {
             error_response('Invalid Status. Must be: ' . implode(', ', $valid_statuses));
         }
     }
-
+    
+    // Builds SQL Statement
     $sql = "UPDATE contributions SET " . implode(', ', $set_clauses) . " WHERE contribution_id = :id";
 
+    // Prepared SQL Statement
     try {
         $stmt = $pdo->prepare($sql);
         $stmt->execute($params);
@@ -233,14 +238,14 @@ function handle_update($input) {
 
 
 // ---------------------------------------------------------------------
-// DELETE — Delete a Contribution
+// DELETE: Deletes existing Contributions
 // Required: contribution_id
-// Note: Associated Votes are deleted automatically (ON DELETE CASCADE).
+// Associated Votes are deleted automatically
 // ---------------------------------------------------------------------
 function handle_delete($input) {
     $pdo = get_db();
 
-    // Validate Input
+    // Validates Input
     $missing = validate_required($input, ['contribution_id']);
     if (!empty($missing)) {
         error_response('Missing Fields: ' . implode(', ', $missing));
@@ -248,13 +253,14 @@ function handle_delete($input) {
 
     $contribution_id = $input['contribution_id'];
 
-    // Check if Contribution exists
+    // Checks if Contribution exists
     $stmt = $pdo->prepare("SELECT contribution_id FROM contributions WHERE contribution_id = :id");
     $stmt->execute([':id' => $contribution_id]);
     if (!$stmt->fetch()) {
         error_response('Contribution not found.', 404);
     }
 
+    // Prepared SQL Statement
     try {
         $stmt = $pdo->prepare("DELETE FROM contributions WHERE contribution_id = :id");
         $stmt->execute([':id' => $contribution_id]);
@@ -268,33 +274,34 @@ function handle_delete($input) {
 
 
 // ---------------------------------------------------------------------
-// VOTE — Cast a Like or Dislike on a Contribution
-// Required: contribution_id, voter_name, vote_type (like|dislike)
-// The Database Trigger automatically updates likes_count/dislikes_count.
-// The UNIQUE Constraint prevents duplicate Votes per Voter.
+// VOTE: Likes or Dislikes a Contribution
+// Required: contribution_id, voter_name, vote_type
+// Database Trigger automatically updates Likes and Dislikes Count
+// UNIQUE Constraint prevents duplicate Votes per Voter.
 // ---------------------------------------------------------------------
 function handle_vote($input) {
     $pdo = get_db();
 
-    // Validate Input
+    // Validates Input
     $missing = validate_required($input, ['contribution_id', 'voter_name', 'vote_type']);
     if (!empty($missing)) {
         error_response('Missing Fields: ' . implode(', ', $missing));
     }
 
-    // Validate Vote Type
+    // Validates Vote Type
     $valid_vote_types = ['like', 'dislike'];
     if (!in_array($input['vote_type'], $valid_vote_types)) {
         error_response('Invalid vote_type. Must be: ' . implode(', ', $valid_vote_types));
     }
 
-    // Check if Contribution exists
+    // Checks if Contribution exists
     $stmt = $pdo->prepare("SELECT contribution_id FROM contributions WHERE contribution_id = :id");
     $stmt->execute([':id' => $input['contribution_id']]);
     if (!$stmt->fetch()) {
         error_response('Contribution not found.', 404);
     }
 
+    // Prepared SQL Statement
     try {
         $stmt = $pdo->prepare("
             INSERT INTO votes (contribution_id, voter_name, vote_type)
@@ -310,7 +317,7 @@ function handle_vote($input) {
         json_response(['message' => 'Vote recorded successfully.'], 201);
 
     } catch (PDOException $e) {
-        // UNIQUE Constraint Violation — Voter already voted on this Contribution
+        // UNIQUE Constraint Violation - Voter already voted on this Contribution
         if ($e->getCode() == '23505') {
             error_response('You have already voted on this Contribution.', 409);
         }