> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cognite.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Working with time series data

> Learn how to aggregate, subscribe to, and visualize time series data using the CDF API.

Learn how to aggregate, subscribe to, and visualize time series data using the CDF API.

<CardGroup cols={2}>
  <Card title="Time series and datapoints API" icon="chart-line" href="/api-reference/concepts/20230101/time-series-data">
    Insert, retrieve, and query time series datapoints.
  </Card>

  <Card title="Time series in data modeling" icon="database" href="/cdf/dm/dm_guides/dm_integrate_with_time_series">
    Integrate time series with your data model using instanceId.
  </Card>

  <Card title="Aggregation" icon="chart-line" href="/dev/concepts/aggregation/index">
    Understand how CDF pre-calculates aggregates for time series and the available aggregation functions.
  </Card>

  <Card title="Calendar and time zone" icon="calendar" href="/dev/concepts/aggregation/calendar">
    Use local time zones and calendar-aligned granularities in aggregate queries.
  </Card>

  <Card title="Data point subscriptions" icon="bell" href="/dev/concepts/data_point_subscriptions/index">
    Subscribe to real-time changes across large sets of time series.
  </Card>

  <Card title="State time series" icon="toggle-on" href="/dev/concepts/resource_types/state_timeseries">
    Track discrete operational states of industrial equipment with predefined states and specialized aggregations.
  </Card>

  <Card title="Status codes" icon="badge-check" href="/dev/concepts/reference/status_codes">
    Reference OPC UA status codes that determine data point quality and affect retrieval and aggregation.
  </Card>

  <Card title="Best practices for plotting charts" icon="chart-area" href="/dev/concepts/reference/ts_plotting_charts">
    Render precise, high-fidelity charts using proper aggregation and data point handling.
  </Card>
</CardGroup>