Can you help me understand from the following tinkercard circuit that when I press the button why is status of pin 7 not coming 1(High) as we can clearly see the possibility of current to split in two paths towards switch and to the pin 7. However, i see status of pin 7 as 0 which I assume should be 1.
Your topic was MOVED to its current forum category which is more appropriate than the original as it is not an Introductory Tutorial
The resistor being connected to 5v is holding pin 7 HIGH when the button is not pressed.
When the button is pressed pin 7 is connected to ground thru the LED. It is also still connected to 5v thru the resistor but because there is less resistance thru the LED the ground connection wins thus the input goes LOW when the button is pressed.
This is the way.
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Thank you for the answer. It makes sense you write. Still there is bit confusion. When the button is pressed pin 7 is connected to ground thru the LED. What do we mean here? are we talking about current flow?
i assume that when button is pressed 5v pin is giving current which is passing through resistor to button to LED and then to ground. how in this same time pin 7 detecting low? what is coming from ground at the same time when the led is glowing and pin 7 is detecting low?
if possible can you gives the directions when button is pressed in which path current is flowing to turn on the LED and what direction of current path is to pin 7?
when current flows through the led the voltage across it is ~1.7v. This is below the threshold at which a logic input will see a "high". The input impedance at pin 7 is virtually infinite so no current flows into it.
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Meaning current is following the low resistance path which is to go through LED to ground when button is pressed since the impedance is very high because of which current doesn't go to pin 7 and it remains low. Am I understanding it correctly? ,
You may rephrase and detail more if you feel so. Thanks alot for answering 
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Almost there, when button is not pressed, the resistor will bring pin 7 to 5V (high). But virtually no current will flow then either...
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The resistor will pull pin 7 towards 5V.
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