ECDH-ECDSA Combination I am doing research on cryptography primitives at a basic level and I faced a question on encryption methods. I understood that ECDH is an approach to for secure key exchange between two parties before the encryption process begins. It is quite useful in symmetric methods that use the same key for encryption and decryption. But I cannot understand the application of key exchange schemes in public-key encryption methods like ECDSA since only public keys are shared between two parties that does not need secure exchange. But such combination (ECDSA/ECDH) seems to happen in protocols like SSL. In what point does exactly secure key exchange methods like ECDH stands in a public key encryption method specifically ECDSA?
ECDH and ECDSA are two different cryptographic primitives. The one isn't build directly upon the other. ECDH and ECDSA both rely on the same computationally hard problem of elliptic curve cryptography of course.

ECDH is a method of performing key agreement. Both parties can establish a secret value by sending only the public key of their ephemeral or static key pair to the other party. If the key pair of one of the parties is trusted by the other party then that key pair may also be used for authentication. This is however not that common. ECDH is the elliptic curve form of the Diffie-Hellman protocol (the DH in the acronym).

ECDSA is, as the name implies, a digital signature algorithm (DSA). It's the elliptic curve form of DSA. It can be used to authenticate the handshake of the TLS protocol. This authentication includes the key agreement parameters used to derive the master secret. The authentication therefore includes the correctness of the session key.

As you can see above, the actual ECDH and ECDSA may be used together in the handshake of the TLS protocol. They are however independent of each other with regards to operation. This is also why ECDH and RSA combinations can exist. ECDH and ECDSA just happen to share the same cryptographic principles.