> For the complete documentation index, see [llms.txt](https://docs.sia.tech/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.sia.tech/get-started-with-sia/sia101.md). # Learn about Sia The Sia Foundation is a non-profit that develops the Sia decentralized storage network. Sia lets you store data directly with operators around the world instead of with a single company, so no one provider can read your files, lock you in, or take your data offline. Sia is decentralized cloud storage secured by a blockchain. It uses spare hard-drive capacity from operators worldwide to create a storage marketplace that is typically cheaper than traditional cloud providers. The network has its own blockchain and a utility token, Siacoin (SC), used to pay for storage. Your files are encrypted on your own device before they're uploaded, so storage providers only ever hold encrypted pieces and can't read your data. Because you hold the keys, you control who can access your files. ## Genesis of Sia Sia was created at HackMIT in 2013 by David Vorick and Luke Champine. The founders formed Nebulous Labs, later Skynet Labs, to develop Sia. The Sia Foundation is a non-profit dedicated to the network's core development. ## How Sia works When you upload a file to Sia, it's encrypted on your machine, split into redundant pieces using [erasure coding](https://devs.sia.storage/docs/core-concepts/erasure-coding), and distributed across many independent storage providers. Providers only receive encrypted pieces, never your whole file, so they can't read your data. Only a subset of the pieces is needed to reconstruct a file, so your data stays available even if some providers go offline. Because the pieces are spread across unrelated providers and you hold the encryption keys, there is no single provider that can read your files, hand over readable copies, or take your data offline. ### Storing data on Sia When you store data on Sia you act as a *renter*: you form contracts with storage providers that set how much data to store, for how long, and at what price. This contract management is handled for you by [Sia Storage](https://sia.storage) (a hosted service) or by running your own [indexer](/store-your-data/setting-up-indexd.md). See [About Storing Your Data](/store-your-data/about-renting.md) for how the pieces fit together. ### Providing storage on Sia Providing storage means contributing spare storage capacity to the network. In return for storing data and periodically proving you still hold it, you earn Siacoin (SC), which you can use to pay for your own storage or exchange for other currencies. See [About Providing Storage](/provide-storage/about-hosting-on-sia.md). ## Sia software The Sia Foundation maintains an open-source software suite for using and operating the network. Which one you need depends on what you want to do — see [Which Sia software do I need?](/get-started-with-sia/sia-software-overview.md) for a side-by-side breakdown. To store data on Sia you run a *client* (an app) that connects to an *indexer* (the backend). The client encrypts your files and moves them to and from storage providers; the indexer manages contracts and keeps your data healthy. ### Sia Storage [Sia Storage](https://sia.storage) is a hosted indexer — it manages contracts and keeps your data healthy for you, with 50 GB free and nothing to run. On its own it's just the backend; you use it through a client such as the Sia Storage app or `s3d`. For most people, the Sia Storage app with a Sia Storage account is the easiest way to start. ### Sia Storage app and s3d These are the clients you use to actually store and retrieve files. The **Sia Storage app** runs on desktop and mobile. **`s3d`** is an S3-compatible gateway that lets existing S3 tools and applications use Sia. Both connect to an indexer — Sia Storage by default — and you can also build your own client with the [Sia Storage SDKs](https://devs.sia.storage). ### indexd `indexd` is the indexer software, for running the backend yourself instead of using Sia Storage. It forms and renews storage contracts with providers, tracks where your data lives, and repairs it in the background. Clients and applications connect to it to store and retrieve data without managing providers themselves. ### hostd `hostd` is the software for storage providers. It has an embedded web UI and an API for managing storage and revenue, and earns Siacoin in exchange for storing encrypted data for the network. ### walletd `walletd` is the standalone wallet server for Siacoin (and Siafund) wallets. It supports multiple wallets and hardware wallets such as Ledger, and can index either just your own addresses or the entire chain. It can hold your seeds to send and receive, or run watch-only — tracking addresses without access to private keys. ### renterd `renterd` is the original all-in-one renter daemon, bundling a wallet, contract management, and an upload/download UI into one program. It still works, but for new projects the indexer-based stack above (or Sia Storage) is preferred. ## Longevity Sia has been running since 2015. Because the software is open-source and the network is decentralized, it can keep operating even without the core development team. Sia has an active community of renters, storage providers, miners, and developers, along with an ecosystem of open-source and commercial software — see the [community ecosystem](https://sia.tech/community-ecosystem). --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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