capacitor. what is happening in this circuit ?

[elektronJack]

Both switches are open at the beginning.
When i close sw1 the led doesn't illuminate.
If i open sw1 then close sw2 the led doesn't
illuminate.
However if i then open sw2 then close sw1 the led flashes once only. I understand that it has something to do with the capacitor but
i can't understand the current flows.

[EEEnthusiast]

When you close SW1, the capacitor gets charged through the series path of the resistor and the LED. It charges us quite quickly and then the current drops to zero. Thats why you see the LED blink.
With SW2 closed, the current is too low (the series resistor is in KOhms) and hence the LED does not glow.
The circuit behaves well as drawn.

[Wimberleytech]

When you close SW2 while SW1 is open, any charge that might be on the capacitor is discharged.  Thus the voltage across the capacitor is zero volts.

When you open SW2 (SW1 still open), nothing changes...there is still zero volts across the capacitor.

The physics of how a capacitor works says that the voltage across a capacitor cannot change instantaneously.

So, when you close SW1, the + side of the capacitor rises instantly to about 12 volts.  Because the voltage across the capacitor cannot change instantly, the - side of the capacitor ALSO rises to about 12 volts and THEN begins discharging through the LED.  The time constant is pretty fast (milliseconds), so you only see a quick blink.