Search engine marketing – Impression VS Clicks/CTR VS Conversions

In search engine marketing, Impression, Clicks or conversions, which is more important?

How you should view the most important metrics regarding your search engine marketing campaigns:
• Impression – this indicates the number of times your ads are shown, and this means the list of keywords you research, does it quantify the traffic or volume users are searching for?
• Clicks/Impression – this indicates how well your ads are written that encourage users to respond to your ads with regards to what they search for
• Conversion – this indicates how well your keywords, ad copies and landing page work together and encourage a user to act within your website, and if they do? This may mean a potential business lead to your company or getting another new customer to your business, and isn’t this what we want when we advertise?
In conclusion, is shall say, whenever we set up a Search engine marketing campaigns, everything start with traffic, so research a proper list of Keywords (1st step), write a good ad text to encourage users to respond to your ads (2nd step), and after you quantify your traffic, qualify your traffic and turn Clicks or visitors to a customers