difference between a network and a circuit

Discussion in 'General Electronics Chat' started by PG1995, May 2, 2011.

  1. PG1995

    Thread Starter Active Member

    Apr 15, 2011
    753
    5
    Hi :)

    The book says:
    Since the elements of an electric circuit can be interconnected in several
    ways, we need to understand some basic concepts of network topology. To
    differentiate between a circuit and a network, we may regard a network as
    an interconnection of elements or devices, whereas a circuit is a network
    providing one or more closed paths. The convention, when addressing
    network topology, is to use the word network rather than circuit. We
    do this even though the words network and circuit mean the same thing
    when used in this context. In network topology, we study the properties
    relating to the placement of elements in the network and the geometric
    configuration of the network. Such elements include branches, nodes,
    and loops.

    A network with b branches, n nodes, and l independent loops will
    satisfy the fundamental theorem of network topology: b = l + n-1


    Could you please give me some simple explanation on distinction between a network and a circuit? It would kind of you.

    Regards
    PG
     
  2. StayatHomeElectronics

    Well-Known Member

    Sep 25, 2008
    864
    40
    It doesn't sound like the author of the book is that convinced about a difference between the two...
     
  3. ifixit

    Distinguished Member

    Nov 20, 2008
    638
    108
    Examples...
    • A road is a circuit that carries vehicles from point A to point B. A city contains a network of roads that connect all points within the city to each other.
    • A datalink is an electric circuit that connects one point to another point. The internet contains a network of many datalinks that connects any point to any point.
    Can you think of some more examples?

    An audio amplifier contains many separate electricial circuits inter-connected together to form an amplication function, but the collection of circuits is not considered a to be a network of circuits because only electrons move between them.

    A network has more to do with inter-connection of information paths than electron paths. If the internet only carried electrons and no meaningful information, then it wouldn't be called the internet, it would be called the interconnect.

    Regards,
    Ifixit
     
    Jack Puddin and PG1995 like this.
  4. BillO

    Well-Known Member

    Nov 24, 2008
    985
    136
    Network is a more general term than circuit.

    A circuit is one type of network.

    Every Circuit is a network.

    There are some networks that are not circuits.
     
  5. nsaspook

    AAC Fanatic!

    Aug 27, 2009
    2,907
    2,163
    The old school (pre-internet) difference:

    A circuit was the direct flow of information from one point to the other and a network was composed of a system of circuits for interconnecting other circuits. A single circuit connection to many points would be a broadcast network. The circuit connection point to a network was called a node.

    A typical circuit could be on a HF point to point link to a receiver station, then to a microwave frame-relay network node sending to a distant station node and then a point to point land-line circuit to the endpoint.

    The complete source to endpoint route would be assigned a circuit ID. If a transmission path in the middle changed but the endpoints stayed the same the circuit ID would be the same.
    http://usmilitary.about.com/od/navynecs/p/IT2319.htm
     
  6. someonesdad

    Senior Member

    Jul 7, 2009
    1,585
    141
    It's semantics -- i.e., whatever the textbook author wants to define. When I took a network theory course back in the 60's, there was no distinction between a network and a circuit. Either that or I don't remember a difference (and lost the textbook somewhere along the way). :p

    It sounds like your textbook wants to define a network as an undirected graph (which might also be an unconnected graph). In graph theory, a circuit is defined as a closed x-x trail (i.e., a walk from node x along at least 3 edges and winding up back at node x; this is also called a cycle). Graph theory has a disgusting number of terms.
     
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