diff --git a/README.md b/README.md
index 0a6db20..cab1a27 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,131 @@
 # rustlike-result
 
 Rust-like Result for Javascript
+
+## Install
+
+```sh
+npm install rustlike-result
+yarn add rustlike-result
+pnpm install rustlike-result
+```
+
+## Usage
+
+This package implement a Rust-like `Result`, nearly all methods are similar to the [Result].
+
+```ts
+// TODO
+```
+
+[result]: https://doc.rust-lang.org/std/result/enum.Result.html
+
+### About Rust `Option`
+
+This package doesn't implement Rust-like `Option`. Handling `undefined`/`null` is not as hard as it was a few years ago, because right now we already have [proposal-optional-chaining] and [proposal-nullish-coalescing] to help handle it.
+
+[proposal-optional-chaining]: https://github.com/tc39/proposal-optional-chaining
+[proposal-nullish-coalescing]: https://github.com/tc39/proposal-nullish-coalescing
+
+## The Implementations for `Result`
+
+The Rust-like `Result` implements the following methods:
+
+| Rust-like `Result` method | Rust `Result` method   |
+| :------------------------ | :--------------------- |
+| isOk                      | [is_ok]                |
+| isOkAnd                   | [is_ok_and]            |
+| isErr                     | [is_err]               |
+| isErrAnd                  | [is_err_and]           |
+| ok                        | [ok]                   |
+| err                       | [err]                  |
+| map                       | [map]                  |
+| mapOr                     | [map_or]               |
+| mapOrElse                 | [map_or_else]          |
+| mapErr                    | [map_err]              |
+| expect                    | [expect]               |
+| unwrap                    | [unwrap]               |
+| expectErr                 | [expect_err]           |
+| unwrapErr                 | [unwrap_err]           |
+| unwrapOr                  | [unwrap_or]            |
+| unwrapOrElse              | [unwrap_or_else]       |
+| unwrapUnchecked           | [unwrap_unchecked]     |
+| unwrapErrUnchecked        | [unwrap_err_unchecked] |
+| and                       | [and]                  |
+| andThen                   | [and_then]             |
+| or                        | [or]                   |
+| orElse                    | [or_else]              |
+| transpose                 | [transpose]            |
+
+Unlike Rust, JavaScript doesn't have the 'Ownership' feature, so some API like `as_ref` is not necessary. These implementations are not implemented:
+
+```md
+<!-- implementations -->
+as_ref
+as_mut
+inspect (unstable)
+inspect_err (unstable)
+as_deref
+as_deref_mut
+iter
+iter_mut
+unwrap_or_default
+into_ok (unstable)
+into_err (unstable)
+copied
+cloned
+flatten (unstable)
+
+<!-- some of trait implementations -->
+clone
+clone_from
+fmt
+hash
+```
+
+[is_ok]: https://doc.rust-lang.org/std/result/enum.Result.html#method.is_ok
+[is_ok_and]: https://doc.rust-lang.org/std/result/enum.Result.html#method.is_ok_and
+[is_err]: https://doc.rust-lang.org/std/result/enum.Result.html#method.is_err
+[is_err_and]: https://doc.rust-lang.org/std/result/enum.Result.html#method.is_err_and
+[ok]: https://doc.rust-lang.org/std/result/enum.Result.html#method.ok
+[err]: https://doc.rust-lang.org/std/result/enum.Result.html#method.err
+[map]: https://doc.rust-lang.org/std/result/enum.Result.html#method.map
+[map_or]: https://doc.rust-lang.org/std/result/enum.Result.html#method.map_or
+[map_or_else]: https://doc.rust-lang.org/std/result/enum.Result.html#method.map_or_else
+[map_err]: https://doc.rust-lang.org/std/result/enum.Result.html#method.map_err
+[expect]: https://doc.rust-lang.org/std/result/enum.Result.html#method.expect
+[unwrap]: https://doc.rust-lang.org/std/result/enum.Result.html#method.unwrap
+[expect_err]: https://doc.rust-lang.org/std/result/enum.Result.html#method.expect_err
+[unwrap_err]: https://doc.rust-lang.org/std/result/enum.Result.html#method.unwrap_err
+[unwrap_or]: https://doc.rust-lang.org/std/result/enum.Result.html#method.unwrap_or
+[unwrap_or_else]: https://doc.rust-lang.org/std/result/enum.Result.html#method.unwrap_or_else
+[unwrap_unchecked]: https://doc.rust-lang.org/std/result/enum.Result.html#method.unwrap_unchecked
+[unwrap_err_unchecked]: https://doc.rust-lang.org/std/result/enum.Result.html#method.unwrap_err_unchecked
+[and]: https://doc.rust-lang.org/std/result/enum.Result.html#method.and
+[and_then]: https://doc.rust-lang.org/std/result/enum.Result.html#method.and_then
+[or]: https://doc.rust-lang.org/std/result/enum.Result.html#method.or
+[or_else]: https://doc.rust-lang.org/std/result/enum.Result.html#method.or_else
+[transpose]: https://doc.rust-lang.org/std/result/enum.Result.html#method.transpose
+
+## More Methods
+### equal
+
+You can not just use `===` or `==` to compare `Result`, so `Result` itself provides an method call `equal` for that.
+
+```javascript
+expect(Ok(1).equal(Ok(1))).toBe(true);
+expect(Ok('hello').equal(Ok('hello'))).toBe(true);
+
+expect(Ok({ foo: 1 }).equal(Ok({ foo: 1 }))).toBe(false);
+expect(Ok([1]).equal(Ok([1]))).toBe(false);
+```
+
+There is no built-in deep-equal support in this package for array, object and some built-in classes like `Date`. If you do want to deeply compare those complex structures, you will have to write your own helper functions.
+
+There is a [proposal] (stage 2) that introduces `Record` and `Tuple` which are compared by content rather than identity. In the future, we can use `Record` and `Tuple` in `Result` so that we don't need to implement custom equality comparison function.
+
+[proposal]: https://github.com/tc39/proposal-record-tuple
+
+## License
+
+MIT
diff --git a/src/__tests__/result.test.ts b/src/__tests__/result.test.ts
index edfd6b0..df658cf 100644
--- a/src/__tests__/result.test.ts
+++ b/src/__tests__/result.test.ts
@@ -418,5 +418,14 @@ describe(`Test method \`${RustlikeResult.name}.prototype.${RustlikeResult.protot
         expect(Err(Ok<number, string>(1)).equal(Err(Err('Some error message')))).toBe(false);
         expect(Err(Err<number, string>('Some error message')).equal(Err(Ok(1)))).toBe(false);
         expect(Ok<number, string>(1).equal(Err('Some error message'))).toBe(false);
+
+        expect(Ok([1]).equal(Ok([1]))).toBe(false);
+        expect(Ok({ foo: 1 }).equal(Ok({ foo: 1 }))).toBe(false);
+        expect(Ok(Ok([1])).equal(Ok(Ok([1])))).toBe(false);
+        expect(Ok(Ok({ foo: 1 })).equal(Ok(Ok({ foo: 1 })))).toBe(false);
+        expect(Err({ message: 'Some error message' }).equal(Err({ message: 'Some error message' }))).toBe(false);
+        expect(Err(Err({ message: 'Some error message' })).equal(Err(Err({ message: 'Some error message' })))).toBe(
+            false,
+        );
     });
 });
diff --git a/src/types.ts b/src/types.ts
index 5c978d5..fbeeab3 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -3,7 +3,7 @@
  * - https://github.com/tc39/proposal-optional-chaining
  * - https://github.com/tc39/proposal-nullish-coalescing
  *
- * We don't need Rust-like Option anymore in most cases.
+ * We don't need Rust-like Option anymore in most cases unless we want functional programming.
  *
  * This type doesn't use the name `Option`,
  * by giving it a different name we can easily know that this is not Rust-like Option.