Call to action (CTA)

A call to action (CTA) is a prompt on a website or a marketing term that refers to the next step a marketer wants its audience or reader to take. 

In order for it to be effective it must be obvious and should instantly follow the marketing message.

Moreover a CTA is normally written as a command or as an action phrase like “Sign Up” or “Buy Now” and generally appears in the form of a button or hyperlink.