After the initial verification of the server(With the help of a certificate, provided by a Certificate Authority ), by the client, the client sends a "Client Key Exchange Message" . This message (Client Key Exchange Message) is encrypted with the public key, provided by the server(So that only server can unlock it).
Client Key Exchange Message is a message sent by the client to the server, containing the "Premaster Secret", which is a random number of 46 bytes.
"Premaster Secret" , is used to create symmetric encryption keys(which are used to encrypt data), and secret key for MAC hash function(For message integrity check on both the server and client side) .
SSL makes use of both Symmetric and Asymmetric Encryption. Asymmetric Encryption is only used for sending "Client Key Exchange Message" (Which we discussed above). Because, client key Exchange message, is the Supper Secret in SSL(Because the symmetric key for data encryption and secret key for MAC,both are derived from "Client Key Exchange Message").
Although a MAC value for integrity check is now placed on our record, our data is still unencrypted. So now the whole data along with the MAC is encrypted with a symmetric Key(which was also shared to the server using "Client Key Exchange Message")
Now this whole encrypted data along with the following header's form a complete record, ready for transmission over TCP.
On receiving a record, which is completely(the fragmented data package, at record layer with all its headers), the the other node can calculate the MAC hash value(because, the secret key for MAC was shared, by the client with "Client Key Exchange Method" ), and then compare it with the MAC attached on the header. Also the server can decrypt the data with the symmetric key ( which was also shared with "Client Key Exchange Method" ) .