# Product analytics (/docs/product-analytics)

Product analytics answers four questions about your events:

- **How much, over time?** [Trends](/docs/product-analytics/insights#trends) count events, people or companies, or add up a number like `amount`.
- **Where do people drop off?** [Funnels](/docs/product-analytics/insights#funnels) measure conversion through a series of steps.
- **Do they come back?** [Retention](/docs/product-analytics/insights#retention) follows groups of people week by week.
- **What's happening right now?** [Activity](#activity) shows every event as it arrives.

Save any of these as an insight and put it on a [dashboard](/docs/product-analytics/dashboards). Product analytics is always on, and it includes [people, cohorts and groups](/docs/people).

<Cards>
  <Card icon="graph" title="Insights" href="/docs/product-analytics/insights">
    Trends, funnels and retention.
  </Card>
  <Card icon="dashboards" title="Dashboards" href="/docs/product-analytics/dashboards">
    Build, customise and share boards of metrics and charts.
  </Card>
</Cards>

## Activity [#activity]

**Activity** in the sidebar lists every event, newest first. Use it to check that a new tracking call works, or to follow one user's session.

- With **live** on, the feed refreshes every few seconds. Turn it off to read without the list moving.
- Filter by event, date range, properties, person, group or cohort.
- Click a row to see all its properties, or click the person to open their profile.
- **Load more** goes further back in time.

<Callout type="info" title="Activity vs Changes">
  **Activity** shows the *events* your product sends. **Changes** on the Home page shows what *people and agents changed* in datahop: insights saved, flags switched, experiments launched.
</Callout>

## Data [#data]

**Data** lists every event and property Datahop has seen, with its type, sample values and volume. You don't declare anything up front: a new event appears here a few seconds after it first arrives. There are four tabs: **Events**, **Event properties**, **Person properties** and **Group properties**.

### Describe your events [#describe-your-events]

Click **Add description…** next to an event or property, type, and press Enter. Everyone in the project sees descriptions, and so do agents, which read them before they write a query.

Compare what an agent sees without and with a description:

- `order_completed` (2,856 events)
- `order_completed` (2,856 events): "Paid order, sent from the server after payment is confirmed. `amount` is in `currency` units, after discounts, before tax."

With the second, the agent knows refunds and failed payments aren't included and that amounts aren't all in one currency. A good description says:

- **when** it fires (browser or server, before or after confirmation);
- the **units and currency** of numbers;
- **known quirks** ("before October this was also sent on retries");
- **what not to use it for** ("for revenue, use `order_completed`, not this").