diff --git a/src/main/c/Georg/tictactoe.c b/src/main/c/Georg/tictactoe.c
index fcade80..241ee34 100644
--- a/src/main/c/Georg/tictactoe.c
+++ b/src/main/c/Georg/tictactoe.c
@@ -8,25 +8,25 @@ void printBoard();
 
 struct ticTacToe GAME;
 
-struct command COMMANDS[MAX_COMMANDS] = {
+struct usrCommand COMMANDS[MAX_COMMANDS] = {
         { 1, "\"start menu\" - startet das menu", startMenu},
         { 2, "\"start game\" - startet das spiel", startGame}
 };
 
 void startTicTacToe(){
-    setbuf(stdout, 0);
+    setbuf(stdout, 0); // for debug output
     printf( "%s\n", getWelcomeMessageTicTacToe() );
     printf( "%s\n\n", getRulesMessageTicTacToe() );
 
-    GAME = createTicTacToe();
+    GAME = createTicTacToe(); // create the "game object"
 
     while( GAME.currentState != -1 ){
-        commandFunction command;
-        printf("search command!\n");
-        command = getCommandById( GAME.currentState + 1);
+        commandFunction usrCommand;
+        //printf("search command!\n");
+        usrCommand = getCommandById( GAME.currentState + 1);
 
-        if( command != NULL)
-            command(0);
+        if( usrCommand != NULL)
+            usrCommand(0); // 0, for non test behavior
         else{
             printf("command not found");
             return;
@@ -64,11 +64,11 @@ int handleCommand( char* input ){
 
 commandFunction getCommandById( int id ){
     commandFunction result = NULL;
-    size_t arraySize = sizeof(COMMANDS) / sizeof(COMMANDS[0]);
+    size_t arraySize = sizeof(COMMANDS) / sizeof(COMMANDS[0]); // calculate size of Array
     for (size_t i = 0; i < arraySize; i++) {
         //printf( "%s", COMMANDS[i].description );
         if( COMMANDS[i].id == id ){
-            result = COMMANDS[i].fun;
+            result = COMMANDS[i].fun; // save the function pointer as result
             break;
         }
     }
@@ -80,22 +80,26 @@ char* getUserInput(){
     printf( ":" );
     fgets(userInput, sizeof(userInput), stdin);
 
-    size_t len = strlen(userInput);
-    if (len > 0 && userInput[len - 1] == '\n') {
-        userInput[len - 1] = '\0';
+    size_t lengthOfInput = strlen(userInput);
+    if (lengthOfInput > 0 && userInput[lengthOfInput - 1] == '\n') {
+        userInput[lengthOfInput - 1] = '\0'; // declare end of command
     }
-
     return userInput;
 }
 
 void initializeBoard( bool board[BORAD_SIZE][BORAD_SIZE] ){
-    for (int i = 0; i < 3; ++i) {
-        for (int j = 0; j < 3; ++j) {
-            board[i][j] = 0;
+    for (int line = 0; line < 3; ++line) {
+        for (int column = 0; column < 3; ++column) {
+            board[line][column] = 0;
         }
     }
 }
 
+/**
+ * The function checks if the user has written a valid command
+ * @param input
+ * @return 1 for a valid command and 0 for an invalid one.
+ */
 int handleGameInput( char* input ){
     if( strstr(input, "set") != NULL ){
         return 1;
@@ -105,7 +109,7 @@ int handleGameInput( char* input ){
 }
 
 int startMenu( int code ){
-    if( code == -1 ){ // command test
+    if( code == -1 ){ // usrCommand test
         return 1;
     }
 
@@ -125,15 +129,16 @@ int startMenu( int code ){
 }
 
 void printBoard(){
+    // calculate the size of the board and print the upper frame
     for( int i = 0; i < BORAD_SIZE*4+1; i++ ){
         printf("-");
     }
     printf("\n");
 
-    for (int i = 0; i < 3; ++i) {
+    for (int line = 0; line < 3; ++line) {
         printf("| ");
-        for (int j = 0; j < 3; ++j) {
-            if( GAME.board[i][j] == true )
+        for (int column = 0; column < 3; ++column) {
+            if( GAME.board[line][column] == true )
                 printf( "X" );
             else
                 printf ( " " );
@@ -143,12 +148,18 @@ void printBoard(){
         printf( "\n" );
     }
 
+    // calculate the size of the board and print the upper frame
     for( int i = 0; i < BORAD_SIZE*4+1; i++ ){
         printf("-");
     }
     printf("\n");
 }
 
+/**
+ * Get a the user input and parse it.
+ * @param input
+ * @return a array with the x and y direction where the user wants to set the marker.
+ */
 int* getMarkerParameters( char* input ){
     int* array = (int*)malloc(2 * sizeof(int));
 
@@ -156,8 +167,8 @@ int* getMarkerParameters( char* input ){
     int firstArgument = input[index-1] - '0';
     int secondArgument = input[index+1] - '0';
 
-    array[0] = firstArgument-1;
-    array[1] = secondArgument-1;
+    array[0] = firstArgument-1; // return x
+    array[1] = secondArgument-1; // return y
 
     return array;
 }
@@ -186,9 +197,9 @@ void handleGame(){
 
     // gameCommand processing
     if( gameCommand == 1 ) { // set marker in field
-        int* params = getMarkerParameters( input );
-        setBoardMarker( GAME.board, params );
-        free(params);
+        int* params = getMarkerParameters( input ); // get the x and y values
+        setBoardMarker( GAME.board, params ); // apply the x and y values in the field
+        free(params); // prent memory leakage
 
         printBoard();
 
@@ -202,17 +213,16 @@ void handleGame(){
 
 bool playerHasWon( bool board[BORAD_SIZE][BORAD_SIZE]){
     bool player = 1;
-    // Überprüfe Zeilen und Spalten
     for (int i = 0; i < 3; i++) {
-        // Überprüfe Zeilen
+        // check the rows
         if ((board[i][0] == player && board[i][1] == player && board[i][2] == player) ||
-            // Überprüfe Spalten
+            // check the columns
             (board[0][i] == player && board[1][i] == player && board[2][i] == player)) {
             return true;  // Spieler hat gewonnen
         }
     }
 
-    // Überprüfe Diagonalen
+    // check the diagonal line
     if ((board[0][0] == player && board[1][1] == player && board[2][2] == player) ||
         (board[0][2] == player && board[1][1] == player && board[2][0] == player)) {
         return true;  // Spieler hat gewonnen
@@ -222,7 +232,7 @@ bool playerHasWon( bool board[BORAD_SIZE][BORAD_SIZE]){
 }
 
 int startGame( int code ){
-    if( code == -1 ){ // command test
+    if( code == -1 ){ // usrCommand test
         return 1;
     }
 
diff --git a/src/main/c/Georg/tictactoe.h b/src/main/c/Georg/tictactoe.h
index efd1d1e..59f90d9 100644
--- a/src/main/c/Georg/tictactoe.h
+++ b/src/main/c/Georg/tictactoe.h
@@ -15,14 +15,14 @@ struct ticTacToe{
 // Typdefinition für einen Funktionszeiger
 typedef int (*commandFunction)( int );
 
-struct command{
+struct usrCommand{
     int id;
     char* description;
     commandFunction fun;
 };
 
 extern struct ticTacToe GAME;
-extern struct command COMMANDS[MAX_COMMANDS];
+extern struct usrCommand COMMANDS[MAX_COMMANDS];
 
 
 void startTicTacToe();