Authentication of the message: Although messages may often include information about the entity sending a message, that information may not be accurate. Digital signatures can be used to authenticate the source of messages. When ownership of a digital signature secret key is bound to a specific user, a valid signature shows that the message was sent by that user.
Integrity: In many scenarios, the sender and receiver of a message may have a need for confidence that the message has not been altered during transmission. Although encryption hides the contents of a message, it may be possible to change an encrypted message without understanding it. However, if a message is digitally signed, any change in the message after signature invalidates the signature.
The cryptographic message syntax or XML digital signature are examples.
Non-repudiation: It is an important aspect of digital signatures. By this property, an entity that has signed some information cannot at a later time deny having signed it. Similarly, access to the public key only does not enable a fraudulent party to fake a valid signature.
A digital signature alone does not provide confidentiality since it does not prevent disclosure of information you would want to keep secret. Encryption would be an example of a mechanism to provide confidentiality.
So it doesn't provide privacy