E.g. you want your temporary website not to be found by Google.
Then you can add a couple of lines to the .htaccess file and create a .htpasswd (to store the user credentials).
AuthType Basic AuthName "My Protected Folder" AuthUserFile /link-to-your-website-folder-above-public/.htpasswd require valid-user
Next create the .htpasswd and generate the content of that file (containing the username and password) using e.g. a htpasswd generator. E.g. this one.