Update README.md

Updating the README.

Author: juneb

README.md

@@ -13,20 +13,18 @@ examples that show common use patterns.
 ## What is the AWS Encryption SDK? 
 
 The AWS Encryption SDK is a
-[client-side](https://docs.aws.amazon.com/dynamodb-encryption-client/latest/devguide/client-server-side.html)
+[client-side](https://docs.aws.amazon.com/crypto/latest/userguide/cryptography-concepts.html#define-client-server-side)
 encryption library that makes it easier for you to encrypt and decrypt data securely in your
 application. It can be used on any type of data. The `encrypt`
 method returns a single, portable formatted message that is easy to store and manage. 
 
-The AWS Encryption SDK is available in [Java](https://docs.aws.amazon.com/encryption-sdk/latest/developer-guide/java.html),
-[Python](https://docs.aws.amazon.com/encryption-sdk/latest/developer-guide/python.html),
-[C](https://docs.aws.amazon.com/encryption-sdk/latest/developer-guide/c-language.html), [JavaScript](https://docs.aws.amazon.com/encryption-sdk/latest/developer-guide/javascript.html), and a [command-line
+The AWS Encryption SDK is available in [C](https://docs.aws.amazon.com/encryption-sdk/latest/developer-guide/c-language.html), [C#/.NET](https://docs.aws.amazon.com/encryption-sdk/latest/developer-guide/dot-net.html), [Java](https://docs.aws.amazon.com/encryption-sdk/latest/developer-guide/java.html), [JavaScript](https://docs.aws.amazon.com/encryption-sdk/latest/developer-guide/javascript.html), [Python](https://docs.aws.amazon.com/encryption-sdk/latest/developer-guide/python.html), and a [command-line
 interface](https://docs.aws.amazon.com/encryption-sdk/latest/developer-guide/crypto-cli.html) that runs on Linux, macOS and Windows.
 
 
-To protect data, the Encryption SDK uses *envelope encryption*. Each item of data is encrypted under a unique data key. Then, the data key is encrypted under a master key so it can be safely stored with the data. Your application does not have to generate or manage the data keys.
+To protect data, the Encryption SDK uses *envelope encryption*. Each item of data is encrypted under a unique symmetric data key. Then the data key is encrypted under a wrapping key that you specify so the encrypted data key can be safely stored with the data. Your application does not have to generate or manage the data keys.
 
-To protect the master key that encrypts the data keys, you can use a web service, such as [AWS Key
+To protect the wrapping key that encrypts the data keys, you can use a web service, such as [AWS Key
 Management Service](https://docs.aws.amazon.com/kms/latest/developerguide/) (AWS KMS), a hardware
 security module (HSM), such as those offered by [AWS
 CloudHSM](https://docs.aws.amazon.com/cloudhsm/latest/userguide/), or your existing key management tools. The AWS Encryption SDK does not require an AWS