Feel good, help a noob- basic resistor placement

Making me understand this will clear up a confusion about circuits I've had since college physics. I built a working EEG from plans for a senior project without truly understanding electronics. Follows:

To conduct current to an LED, for instance, I've seen the resistor placed both
1. after the LED towards the - end, or ground
2. before the LED, towards the + terminal

This confuses me greatly. My impression is that current should be limited appropriately before reaching the LED or other component, therefore placing the resistor before the LED towards the + terminal. Why am I seeing both placements in schematics?

Help a noob. Thank you!

*towards the -end, or +terminal, referencing the power supply.

Because it doesn't matter where you place the resistor in a series circuit. Think of it like a hose with water flowing through it. The resistor is like placing a clamp on the hose and tightening it until the flow of water is constricted (how much it is constricted is the quantity of resistance). It doesn't matter where, along the hose, you place the clamp, it's still going to restrict the flow by the same amount, and in the same way. Lets say you cut the hose near the halfway point of it's length and install a flow meter. The meter will read the same whether you place the clamp above the meter or below the meter, because the flow of water in the hose is a function of the ability of water to flow along the whole hose.

In an electrical circuit, it's the same. The flow of electricity is a function of the total resistance in the circuit. The resistance in a series leg is the sum of all the resistances in the current path. The amount of current is the voltage applied across this circuit, divided by the total resistance (ohms law). So, the current will be the same whether the resistor precedes the LED or follows the LED.

I do understand that. You're great, thank you, in large part for making that simple. On to tackling parallel circuits then. I'll see if I can get this one on my own.

Steve, I do find it interesting that this effect is instantaneous. If a hose was clamped and then the water was turned on with no water in the hose, then the amount of water flowing would not be restricted until hitting that clamp. However, I understand your analogy in the scenario that water was already in the hose stationary with clamp in place, then the water was turned on from the source.

It's an analogy. It make it more like a wire, think of it as a hose that is already full of water. In a wire, the electrons are the water, and they are already there. The power source merely moves them.