Marketing Cloud application uses JavaScript code processed by Marketing Cloud servers. Instead of using the browser to render the JavaScript on the client-side computer, Marketing Cloud executes the JavaScript on the server when rendering. Use Core server-side JavaScript functions to personalize landing pages and create applications to run on Marketing Cloud. Use Platform server-side JavaScript functions to work with messages, landing pages, and applications. You should exclusively use AMPscript or Platform object server-side JavaScript functions in email messages and reserve your use of Core library server-side JavaScript to landing pages and applications. You can use SSJS just like ampscript to insert data/update data into a Data Extension . <script runat="server"> var rows = Platform.Function.InsertData("CustomerData",["FirstName","LastName","Email"],["Joe","Smith","jsmith@example.com"]); </...