Originally Posted by: kumarvartak 
Yes Thanks, have downloaded the same and have a better understanding, though my understanding will be tested when I actually try it out on my layout, hoping for the best. Thanks again
Kumar
India
Hi Kumar, ok that's great, at least you have a basis to work from.
To answer your specific question about the difference between the two track types;
The 5146/5147
'Switching / Circuit' track sections are directional, and designed for momentary contact only. Mainly to operate a solenoid device such as a signal, a turnout or a relay to control other devices. Solenoid devices should not have power continually applied otherwise the solenoid will overheat and can burn out.
The Switching/Circuit tracks also offer the advantage of being directional so that a train can pass in one direction and trigger one circuit, whereas a train going in the opposite direction would trigger a different circuit.
These track sections are only triggered by a passing pickup shoe, which may be a good or bad thing depending on your layout design. Additional pickup shoes (for example on coaches with lighting) may trigger a circuit again after it has been reset leading to unexpected results so you need to allow for the longest length train likely to pass that track section.
The 5104/5105
Contact Track sections are activated by the wheels and are designed for situations where you do want continual power. One good example of this is to turn on station lights while a train is passing through the station. Contact track sections have a start track and an end track, and all the sections between them are also isolated, so you need at least as many sections as the length of the station.
A second use is the electric Barrier Arm level crossing where you want the boom arms to lower a little before the train goes through the crossing and not raise until the train is well clear. So long as any Loco or item of rolling stock is anywhere on the isolated section, the circuit is completed through the wheels.
A third use is for track occupancy detection, especially useful if you make a track diagram control board where you can have lights to indicate a section of track and whenever a train is on that section, the light will be on. This can be visually quite attractive, but also helpful in a long tunnel or other hidden section of your railway so that you can still 'see' where your trains are from the diagram board. it's also very helpful if you were to have a hidden storage yard or passing loop, where you can tell at a glance of the diagram board whether there is already a train on that siding.
This feature is rarely used and I personally think it adds a heap of 'play value' to any layout, big or small.
Note that these track sections do not use a passing pickup shoe, they use the wheels. Yes a small section of paper, insulation tape etc is fine to separate the third-rail contacts to create your isolated sections.
The attached image below from a later version of the 0341 Signal Manual should help (with thanks to
Bigdaddynz
for the original scan).
About the best thing you can do is experiment with the track types with various solenoid devices and some standard Marklin lights and see the result with your own eyes. You can't really go wrong with the signal manual as a reference.
Does this help? Keep the questions coming
Regards
Steve
cookee_nz attached the following image(s):