With each interaction to your website or app, an event and parameters containing information about the interaction are sent to analytics. Events are user interactions with a website or app that can be measured, like a video view. An event could be when a user first opens your app, watches a video, or views a page on your website.

Events are sent with additional data called event parameters. Event parameters add context to the event. Event parameters are additional pieces of information sent with events that can further specify an action the user took or add further context to the event, like the name of the video or how long the user watched it.

For example, when someone watches a video on your website, an event is fired when someone clicks play and is associated with event parameters, like the name of the video and how long the video was watched.

Along with events and event parameters, user data, like geographic location and the device being used, are also sent. These are called user properties. These are attributes about who’s using your app or website that can help you better understand segments of your user bas

A conversion is an event that you consider important to your business, such as a purchase or a download.

To visually represent this data in reports, analytics uses dimensions and metrics.

• a dimension is an attribute of your data. It describes your data, and it’s usually text as opposed to numbers.
• a metric is a quantitative measurement, such as an average, a ratio, and a percentage. It’s always a number as opposed to text.

Dimensions answer the question “who, what, or where?”, while metrics answer the question “how many?”

References

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