Skype uses P2P (peer-to-peer) technology to connect you with other users. It offers several features, including SkypeOut calling from Skype to regular and mobile phones worldwide, conference calling, and secure file transferring. You can also now share your screen with other users.nd because so many people use Skype, it's likely you can message or call just about anyone you know right from the app. Screen share: It's now possible to share your screen with other users during a Skype call.
UDP is a minimal message-oriented transport layer protocol that is documented in RFC 768. UDP provides no guarantees to the upper layer protocol for message delivery and the UDP layer retains no state of UDP messages once sent. For this reason, UDP sometimes is referred to as Unreliable Datagram Protocol. A number of UDP's attributes make it especially suited for certain applications.
Quick and short answer, both use UDP. DNS also uses TCP for some functions -- such server to server communication (zone transfers) or large queries (IPv6 and otherwise). UDP is the 'default' for the average DNS query (client querying a server for a single record). The use of the layer 4 protocol provides the 16 bit port number, which provide DNS the ability to support multiple connections, etc. DHCP uses UDP ports 67 and 68 - to separate client and server functions. The server listens on port 67, and the client 68. DHCP initially does a layer 2 broadcast, as a method of discovery of the server. This is important because the client has no IP address yet, nor does it know the servers IP.