---
title: Introduction
description: "The following guide aims to provide examples to help you start building Bitcoin-based applications. To make the best use of this document, you may want to install the current version of Bitcoin Core, either from [source](https://github.com/bitcoin/bitcoin) or from a [pre-compiled executable](https://bitcoin.org/en/download). Once installed,…"
url: "https://bitcoindevelopers.org/docs/examples/introduction-examples/"
updated: "2025-05-14"
category: Examples
---

# Introduction

The following guide aims to provide examples to help you start building Bitcoin-based applications. To make the best use of this document, you may want to install the current version of Bitcoin Core, either from [source](https://github.com/bitcoin/bitcoin) or from a [pre-compiled executable](https://bitcoin.org/en/download).

Once installed, you’ll have access to three programs: `bitcoind`, `bitcoin-qt`, and `bitcoin-cli`.

- `bitcoin-qt` provides a combination full Bitcoin [Peer](https://bitcoindevelopers.org/encyclopedia/peer/) and [Wallet](https://bitcoindevelopers.org/encyclopedia/wallet/) frontend. From the Help menu, you can access a console where you can enter the [RPC](https://developer.bitcoin.org/reference/rpc/index.html) commands used throughout this document.
- `bitcoind` is more useful for programming: it provides a full [Peer](https://bitcoindevelopers.org/encyclopedia/peer/) which you can interact with through [RPCs](https://developer.bitcoin.org/reference/rpc/index.html) to port 8332 (or 18332 for [Testnet](https://bitcoindevelopers.org/encyclopedia/testnet/)).
- `bitcoin-cli` allows you to send [RPC](https://developer.bitcoin.org/reference/rpc/index.html) commands to `bitcoind` from the command line. For example, `bitcoin-cli help`

All three programs get settings from `bitcoin.conf` in the `Bitcoin` application directory:

- Windows: `%APPDATA%\Bitcoin\`
- OSX: `$HOME/Library/Application Support/Bitcoin/`
- Linux: `$HOME/.bitcoin/`

To use `bitcoind` and `bitcoin-cli`, you will need to add a [RPC](https://developer.bitcoin.org/reference/rpc/index.html) password to your `bitcoin.conf` file. Both programs will read from the same file if both run on the same system as the same user, so any long random password will work:

```
rpcpassword=change_this_to_a_long_random_password
```

You should also make the `bitcoin.conf` file only readable to its owner. On Linux, Mac OSX, and other Unix-like systems, this can be accomplished by running the following command in the Bitcoin application directory:

```
chmod 0600 bitcoin.conf
```

For development, it’s safer and cheaper to use Bitcoin’s test [network](https://developer.bitcoin.org/devguide/p2p_network.html) ([Testnet](https://bitcoindevelopers.org/encyclopedia/testnet/)) or [Regression test mode](https://bitcoindevelopers.org/encyclopedia/regression-test-mode/) ([Regtest](https://bitcoindevelopers.org/encyclopedia/regtest/)) described below.

Questions about Bitcoin use are best sent to the [BitcoinTalk forum](https://bitcointalk.org/index.php?board=4.0) and [IRC channels](https://en.bitcoin.it/wiki/IRC_channels). Errors or suggestions related to documentation on Bitcoin.org can be [submitted as an issue](https://github.com/bitcoin-dot-org/bitcoin.org/issues) or posted to the [bitcoin-documentation mailing list](https://groups.google.com/forum/#!forum/bitcoin-documentation).

In the following documentation, some strings have been shortened or wrapped: “\[…\]” indicates extra data was removed, and lines ending in a single backslash “\\” are continued below. If you hover your mouse over a paragraph, cross-reference links will be shown in blue. If you hover over a cross-reference link, a brief definition of the term will be displayed in a tooltip.