Simple flashing light by transistor BC548 circuit and explanation

This circuit basically the base of LED Flashing circuit, the character generally be have Transistor stay 2 work alternate be be like the automatic switch that alternate work. if wasp output at C pin of Q1 or Q2 as a result get Frequency signal.
Operation of the circuit assume the Q1 run before LED1 will be lit, so the current flows through LED1, R1 through pin C out of leg E of Q1 at the same current will flow through LED2, R4 and the charge on C2 left delete right B positive stand out through the leg C of Q1, but the current lines are not enough to make light LED2 when C2 charges to the voltage BE value of less than 0.7V, resulting in downtime LED1 off Q1 and Q2. LED2 C1 bright start running positive charge left and right negative Q1 Q2 stopped off LED2 will start running again. The work is part of the circuit so indefinitely.