In an electric circuit, something called electric charge flows from the batteries (or power supply) through the bulbs, motors, bells etc (together called the components of the circuit). There must be a complete loop from one end (terminal) of the battery to the other with no gaps or the charge will not flow. We call this flow of charge an electric current (like the flow of water in a river is called the current). The current can be measured using an ammeter in units called ampères (amps, symbol A for short). In the virtual laboratory, the figures are given in milliamps (mA) which are thousandths of amps.
Perhaps surprisingly, the current is not used up as it flows through a component in the circuit. This is a bit like water turning a water wheel – the water is not used up.
If there is a branch in the circuit the current in each branch adds up to give the current in the main circuit. This is also like water – think of the current in a river splitting into two branches as it goes round an island.
An electrical circuit with no branches is called a series circuit. All the current flows through all of the components one after the other.
A circuit with two or more branches is called a parallel circuit. The current splits, some flowing through one branch and the rest through the others.
The batteries (or power supply) are what drive the current round the circuit. The more batteries, the faster the flow of electric charge and the greater the current.
Now go back to the intro and think about the questions there.