To understand how many users are coming from various devices, like computers or mobile phones, you run a report that shows this data, per device, over the past 30 days. In this report, which of these is considered a "metric" in Google Analytics?

In Google Analytics, reports are built using dimensions and metrics. It's crucial to understand the difference:

• Dimensions are attributes or characteristics of your data. They are typically descriptive words, not numbers. They answer questions like "what," "who," or "where." Examples include Device Category, Country, or Traffic Source.
• Metrics are the quantitative measurements associated with a dimension. They are the numbers in your reports that answer "how many?" or "how much?" Examples include Users, Sessions, or Conversion Rate.

Analysis of Correct Answer(s)

• How many users were on mobile phones: This is the correct answer because it represents a metric. It is a specific numerical count (Users) that measures the volume of traffic for a particular dimension value ("mobile phones").

Analysis of Incorrect Options

• The device types, desktops and mobile phones: This is a dimension. Device Category is the attribute that describes the type of device used.
• The date range setting for the last 30 days: This is a configuration setting that filters the data shown in the report. It is neither a dimension nor a metric.
• Where users came from before reaching your site: This refers to a dimension, such as Source / Medium or Channel. It describes the origin of the traffic, which is a characteristic.