# Using Client SDK 5 to work with AWS CloudHSM
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 AWS CloudHSM includes two major Client SDK versions: 
+ Client SDK 5: This is our latest and default Client SDK. For information on the benefits and advantages it provides, see [Benefits of AWS CloudHSM Client SDK 5](client-sdk-5-benefits.md).
+ Client SDK 3: This is our older Client SDK. It includes a full set of components for platform and language-based applications compatibility and management tools.

For instructions on migrating from Client SDK 3 to Client SDK 5, see [Migrating from AWS CloudHSM Client SDK 3 to Client SDK 5](client-sdk-migration.md).

This topic describes Client SDK 5. To check what version of Client SDK you're using, see 

**Topics**
+ [Benefits of AWS CloudHSM Client SDK 5](client-sdk-5-benefits.md)
+ [AWS CloudHSM Client SDK 5 supported platforms](client-supported-platforms.md)
+ [PKCS \$111 library for AWS CloudHSM Client SDK 5](pkcs11-library.md)
+ [OpenSSL Dynamic Engine for AWS CloudHSM Client SDK 5](openssl-library.md)
+ [OpenSSL Provider for AWS CloudHSM Client SDK 5](openssl-provider-library.md)
+ [Key storage provider (KSP) for AWS CloudHSM Client SDK 5](ksp-library.md)
+ [JCE provider for AWS CloudHSM Client SDK 5](java-library.md)