# The basic concepts (/overview/concepts)

Before choosing a product, understand what you own, how its value can change and how you can leave. These five concepts apply throughout Akashi, although each product implements them differently.

## Yield is a result, not a promise [#yield-is-a-result-not-a-promise]

**Yield** is the return generated by a position. For example, lending can earn interest from borrowers. Other positions can earn trading fees or income from underlying assets. Income can change over time, and losses or costs can outweigh it.

An annualised rate expresses a rate over a year for comparison. It does not promise that a position will keep earning at that rate. Read [where vault yield comes from](/invest/yield) and [how Discover compares opportunities](/akashi/discover).

## A position is what you actually own [#a-position-is-what-you-actually-own]

A **position** is your investment in a particular product. It might be a balance in a lending market, a receipt token, or Akashi vault shares. The same USDC starting asset can lead to very different positions.

Discover helps you choose individual positions. A vault holds several allocations behind your single share position. Check the product and receipt after a deposit. The name of the starting asset alone does not identify what you now own.

## Shares separate count from value [#shares-separate-count-from-value]

A **share** represents a part of a vault. Owning 1,000 shares does not necessarily mean owning 1,000 USDC.

Illustrative example: at 1 USDC per share, 1,000 shares are worth 1,000 USDC. At 1.02, the same count is worth 1,020. At 0.90, it is worth 900. The count stays the same while the value changes. Real execution also depends on valuation bounds, rounding, costs and the vault's conditions.

Read [shares and your position](/invest/shares) for the distinction between an estimated value and an executable amount.

## Liquidity determines what can leave now [#liquidity-determines-what-can-leave-now]

**Liquidity** describes how readily assets can be converted into the amount needed for an exit. A position can have value without having enough available USDC to pay everyone immediately.

A vault withdrawal has a request stage, a funding stage and a claim stage. The end of a notice period is not a promise that all requested shares can be funded. An external protocol accessed through Discover has its own exit rules. Read [vault withdrawals](/invest/withdraw) or [direct deposits and withdrawals](/akashi/deposit-and-withdraw) for the relevant path.

## Risk has more than one source [#risk-has-more-than-one-source]

A position can lose value because of an investment loss, a token losing its peg, or a contract failure. It can also be difficult to exit without an immediate loss in its reported value. Those are different problems.

Senior and Junior describe the order in which vault tranches absorb losses. Discover grades describe modelled risk factors. A Junior cushion and a good grade are different concepts, and neither is outside insurance.

Start with [vault risks](/invest/risks), [the Discover methodology](/akashi/methodology) and [security](/resources/security). The [glossary](/resources/glossary) defines the more detailed terms as you encounter them.