TCP/IP protocols are the middle two two tiers of the Internet protocol. 

IP protocol used to move packets between any two nodes on network.

TCP protocol used for the overall trip between source and destination systems.

Internet (IP or Internet level) Packets or Datagrams (conceptual) 
  Packet consists of source & destination address, data, & control.
    (also check out www.freesoft.org/CIE/Course/Section3/7.htm)
 
  IP packets are encapsulated in the network frame (data-link level).
 
  As packet moves from network to network, frame stripped and frames
    appropriate to specific technology applied.

  Also IP packet modified to handle variations of TCP/IP implementation 
    at this particular jump.
   
  TCP level packets (TCP,UDP,etc.) are encapsulated in the IP packet. 
  
See wikipedia.org for topics :  
   "tcp/ip", "IPv4", "IPv6" "4in6" "4on6"