CPC (Cost Per Click) bidding allows you to set a maximum price on the cost of someone clicking on your AdWords ads. This bidding method gives you good value because you pay only when a viewer is interested enough to click your ad.
CPV (Cost Per View) bidding is the default way to set the price you'll pay for your AdWords video ads. While traditional display ads charge you for impressions, with CPV you pay only when a viewer watches your video.
CPM (Cost Per Impressions)- This is the amount you pay each time your ad is displayed on Google Search network or Display network. You pay for impressions for your ad as opposed to clicks as in CPC.
Suppose I wish to inform my customers about a recent event I am planning to launch in my city then I will choose the CPM model that will help my ad to reach a wide variety of audience without paying for every clicks.