> For the complete documentation index, see [llms.txt](https://docs.tronsave.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tronsave.io/concepts.md).

# Concepts

- [Energy & Bandwidth](https://docs.tronsave.io/concepts/energy-and-bandwidth.md): The two resources every TRON transaction consumes — and why renting them saves money.
- [The Rental Model](https://docs.tronsave.io/concepts/rental-model.md): How TronSave's order-book marketplace matches TRON Energy buyers with providers — price tiers, order fills, on-chain delegation, and duration.
- [Order Types](https://docs.tronsave.io/concepts/order-types.md): Every way to buy on TronSave — Normal, Pending, Smart, ZapBuy, Auto Buy, Fast Charge.
- [Staking 2.0](https://docs.tronsave.io/concepts/staking-2.0.md): How TRON Stake 2.0 turns staked TRX into Energy — the yield formula, the 14-day unstaking period, and why staking powers TronSave's rental supply.
- [Pricing & APY](https://docs.tronsave.io/concepts/pricing-and-apy.md): How TRON Energy rental prices are set with unitPrice tiers, and how provider APY (around 18%) is calculated from rental income and voting rewards.
- [Glossary](https://docs.tronsave.io/concepts/glossary.md): Glossary of TRON energy rental terms used across the TronSave docs — Energy, Bandwidth, SUN, Stake 2.0, delegation, order book, and API fields.