---
title: Get started with Flux
description: Get started with Flux by learning important concepts of the Flux language.
url: https://docs.influxdata.com/flux/v0/get-started/
estimated_tokens: 1902
product: Flux
version: v0
---

# Get started with Flux

Flux is a **functional data scripting** language designed to unify querying, processing, analyzing, and acting on data into a single syntax.

## Flux overview

To understand how Flux works conceptually, consider the process of treating water. Water is pulled from a source, limited by demand, piped through a series of stations to modify (remove sediment, purify, and so on), and delivered in a consumable state.

## Basic Flux query

Like treating water, a Flux query does the following:

1. Retrieves a specified amount of data from a source.
2. Filters data based on time or column values.
3. Processes and shapes data into expected results.
4. Returns the result.

To see how to retrieve data from a source, select the data source: InfluxDB, CSV, or PostgreSQL.

<!-- Tabbed content: Select one of the following options -->

**InfluxDB:**

```js
from(bucket: "example-bucket")
    |> range(start: -1d)
    |> filter(fn: (r) => r._measurement == "example-measurement")
    |> mean()
    |> yield(name: "_results")
```

**CSV:**

```js
import "csv"

csv.from(file: "path/to/example/data.csv")
    |> range(start: -1d)
    |> filter(fn: (r) => r._measurement == "example-measurement")
    |> mean()
    |> yield(name: "_results")
```

**PostgreSQL:**

```js
import "sql"

sql.from(
    driverName: "postgres",
    dataSourceName: "postgresql://user:password@localhost",
    query: "SELECT * FROM TestTable",
)
    |> filter(fn: (r) => r.UserID == "123ABC456DEF")
    |> mean(column: "purchase_total")
    |> yield(name: "_results")
```

<!-- End tabbed content -->

Each example includes the following functions (in the order listed):

-   [`from()`](/flux/v0/stdlib/influxdata/influxdb/from/) to retrieve data from the data source.
-   [Pipe-forward operator (`|>`)](/flux/v0/get-started/syntax-basics/#pipe-forward-operator) to send the output of each function to the next function as input.
-   [`range()`](/flux/v0/stdlib/universe/range/), [`filter()`](/flux/v0/stdlib/universe/filter/), or both to filter data based on column values.
-   [`mean()`](/flux/v0/stdlib/universe/mean/) to calculate the average of values returned from the data source.
-   [`yield()`](/flux/v0/stdlib/universe/yield/) to yield results to the user.

*For detailed information about basic Flux queries, see [Flux query basics](/flux/v0/get-started/query-basics/).*

[Flux data model](/flux/v0/get-started/data-model/)

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