update stack details

Signed-off-by: Gaurav Gahlot <[email protected]>

README.md

@@ -7,34 +7,56 @@
 
 This repository is [Experimental](https://github.com/packethost/standards/blob/master/experimental-statement.md) meaning that it's based on untested ideas or techniques and not yet established or finalized or involves a radically new and innovative style! This means that support is best effort (at best!) and we strongly encourage you to NOT use this in production.
 
-It is comprised of following five major components:
+## What's Powering Tinkerbell?
 
-1.  A DHCP server ([boots](https://github.com/tinkerbell/boots))
-2.  A workflow engine (tink, this repository)
-3.  A metadata service ([hegel](https://github.com/tinkerbell/hegel))
-4.  An in-memory installation environment([osie](https://github.com/tinkerbell/osie))
-5.  A controller/handler of BMC interactions([pbnj](https://github.com/tinkerbell/pbnj))
+The Tinkerbell stack consists of several microservices, and a gRPC API:
 
-The workflow engine is comprised of a server and a CLI, which communicates over gRPC.
-The CLI is used to create a workflow and its building blocks: templates and targeted hardware.
+### Tink
+
+[Tink][1] is the short-hand name for the tink-server, tink-worker, and tink-cli.
+`tink-worker` and `tink-server` communicate over gRPC, and are responsible for processing workflows.
+The CLI is the user-interactive piece for creating workflows and their building blocks, templates and hardware data.
+
+### Boots
+
+[Boots][2] is Tinkerbell's DHCP server.
+It handles DHCP requests, hands out IPs, and serves up iPXE.
+It uses the Tinkerbell client to pull and push hardware data.
+It only responds to a predefined set of MAC addresses so it can be deployed in an existing network without interfering with existing DHCP infrastructure.
+
+### Hegel
+
+[Hegel][3] is the metadata service used by Tinkerbell and OSIE.
+It collects data from both and transforms it into a JSON format to be consumed as metadata.
+
+### OSIE
+
+[OSIE][4] is Tinkerbell's default an in-memory installation environment for bare metal.
+It installs operating systems and handles deprovisioning.
+
+### Hook
+
+[Hook][5] is the newly introduced alternative to OSIE.
+It's the next iteration of the in-memory installation environment to handle operating system installation and deprovisioning.
+
+### PBnJ
+
+[PBnJ][6] is an optional microservice that can communicate with baseboard management controllers (BMCs) to control power and boot settings.
 
 ## Building
 
-Use `make help` Luke.
+Use `make help`.
 The most interesting targets are `make all` (or just `make`) and `make images`.
 `make all` builds all the binaries for your host OS and CPU to enable running directly.
 `make images` will build all the binaries for Linux/x86_64 and build docker images with them.
 
-## Workflow
-
-A workflow is a framework responsible for handling flexible, bare metal provisioning, that is...
-
--   standalone and does not need the Packet API to function
--   contains `Boots`, `Tink`, `Hegel`, `OSIE`, `PBnJ` and workers
--   can bootstrap any remote worker using `Boots + Hegel + OSIE + PBnJ`
--   can run any set of actions as Docker container runtimes
--   receive, manipulate, and save runtime data
-
 ## Website
 
 For complete documentation, please visit the Tinkerbell project hosted at [tinkerbell.org](https://tinkerbell.org).
+
+[1]: https://github.com/tinkerbell/tink
+[2]: https://github.com/tinkerbell/boots
+[3]: https://github.com/tinkerbell/hegel
+[4]: https://github.com/tinkerbell/osie
+[5]: https://github.com/tinkerbell/hook
+[6]: https://github.com/tinkerbell/pbnj