docs: add key terms and table of contents

README.md

@@ -15,20 +15,21 @@ With Open Saves, game developers can run a cloud-native storage system that is:
 - Fast: With a built-in caching system, Open Saves optimizes data placements based on access frequency and data size, all to achieve both low latency for smaller binary objects and high throughput for big objects.
 - Scalable: The Open Saves API server can run on either [Google Kubernetes Engine](https://cloud.google.com/kubernetes-engine), or [Cloud Run](https://cloud.google.com/run). Both platforms can scale out to handle hundreds of thousands of requests per second. Open Saves also stores data in Google [Datastore](https://cloud.google.com/datastore) and [Cloud Storage](https://cloud.google.com/storage), and can handle hundreds of gigabytes of data.
 
-For more information, see the [Overview](./docs/overview.md). To get started with deploying Open Saves, check out the [deployment guide](./docs/deploying.md).
+## Table of Contents
 
-For more information about the API, refer to the [API reference](./docs/reference.md).
+- [Overview](./docs/overview.md)
+- [Key terms](.docs/key-terms.md)
+- Using Open Saves
+  - [Deployment guide](./docs/deploying.md)
+  - [API reference](./docs/reference.md)
+- Contributing to Open Saves
+  - [How to contribute](docs/contributing.md)
+  - [Open Saves development guide](docs/development.md)
 
 ## Disclaimer
 
 This software is currently beta, and subject to change. It is not yet ready to serve production workloads.
 
-## Contributing to the project
-
-Check out [How to Contribute](docs/contributing.md) before contributing to the project.
-
-The [Open Saves development guide](docs/development.md) has detailed instructions on getting the source code, making changes, testing, and submitting a pull request to Open Saves.
-
 ## Code of Conduct
 
 Participation in this project comes under the [Contributor Covenant Code of Conduct](docs/code-of-conduct.md).

docs/key-terms.md

@@ -0,0 +1,35 @@
+# Key Terms
+
+This page describes concepts upon which Open Saves is built. For an overview of Open Saves, see [Overview](./docs/overview.md). 
+
+### Store
+
+A [store](https://pkg.go.dev/github.com/googleforgames/[email protected]/api#Store) is an immutable container for a collection of related records. You create and receive stores using a unary RPC.
+
+### Record
+
+A [record](https://pkg.go.dev/github.com/googleforgames/[email protected]/api#Record) is a mutable data entity that belongs to a store. You create and retrieve records using a unary RPC.
+
+A record can consist of the following:
+
+* [Property](https://pkg.go.dev/github.com/googleforgames/[email protected]/api#Property): the field where typed data is stored as an integer, string, or boolean.
+
+* [Blob](https://pkg.go.dev/github.com/googleforgames/[email protected]/api#BlobMetadata): a single large object used for storing images, videos, game state data, or other types of data in Cloud Storage. Blobs are created and retrieved by a streaming RPC (`Create/GetBlob`).
+
+* [Chunked blob](https://pkg.go.dev/github.com/googleforgames/[email protected]/api#ChunkMetadata): a large blob split into smaller chunks that are uploaded in parallel. 
+To upload a chunked blob, call `CreateChunkedUploadRequest` with the chunk size and get a session ID to upload chunks via a streaming API. When downloading a chunked Blob, a streaming API is also used after you call `GetBlobChunkRequest`.
+
+Blobs and chunked blobs are treated as separate types of data.
+
+### Owner
+
+You can specify the owner of a store or record using the `OwnerId` field.
+
+### Tags
+
+Tags are a list of strings associated with stores or records that you can use to organize and query your resources. You can edit the tags using `UpdateStore` or `UpdateRecord`.
+
+### Hints
+
+You can use [hints](https://pkg.go.dev/github.com/googleforgames/[email protected]/api#Hint) to indicate how you want the server to behave. For example, use cache hints to instruct the server to skip the cache when retrieving records or to not cache records. 
+You can also use blob hints to force data to be stored in Cloud Storage or force a blob to be stored in the metadata server. Blob and cache hints can be used in tandem, such as when you want to skip the cache when storing a record but also force the property as an inline blob.