They can be both. E.g. MPLS-TP or Connection-Oriented-Ethernet (COE) are connection oriented.

No

Connection-oriented

Connection-Oriented means that when devices communicate, they perform handshaking to set up an end-to-end connection. Connection-Oriented systems can only work in bi-directional communications environments.

Connection-less means that no effort is made to set up a dedicated end-to-end connection. Walkie-talkies, or Citizens Band radios are a good examples of connection-less communication.

Connection oriented is more reliable because there is an acknowledgment received from data receiver (destination) that the data is receiving and transfer is successful which is not received from connection less protocol.