ProtocolVersion in the ClientHello message ssl

SSL3.0 specification/page22 provides the following structure description:

The structure of the client hello is as follows.

 struct {
     ProtocolVersion client_version;
     Random random;
     SessionID session_id;
     CipherSuite cipher_suites<2..2^16-1>;
     CompressionMethod compression_methods<1..2^8-1>;
 } ClientHello;

Well, Random structure is described as follows:

struct {
       uint32 gmt_unix_time;
       opaque random_bytes[28];
} Random;

It's not clear what about the other structures? ProtocolVersion, CipherSuite, CompressionMethod... How should they be defined?