A question about star grounding

[Addni]

I've been hearing a lot about star grounding on this forum, and trying to figure out what it is.

I've been working as an electrician for about 4 years, and have completed all I need for bachelor degree in school (I just need to finish a specific amount of time working to be able to take the bachelor degree).

What other type of grounding is there, besides star grounding ? I've only heard of one type of grounding in school, so I'm a bit confused.

I'm linking a document from school, This is an example of how the electrical box (not finding the word I need) should be connected.
Link: http://www.shefakedthehalo.com/arni/star.jpg

This is an example of a small apartment

So, starting from the bottom, I Get a black and yellow/green from the electrical distributor (again, don't know the word). They, have their transformer somewhere in the street that changes the high-voltage down to 230/400V, then where the transformer is they have a copper wire running in the ground.

from their transformer it goes into an disturbution box that is usually every 4-5 houses. There they have another copper wire for grounding, and then it goes into my house.

In the base of my house (word?) I have a lot of construction iron, that are welded together at a few places, then I get one wire coming into the "TENGIBOX" (connecting box) on the picture I linked.

The ground from the street goes into the PEN, along with the grounding in the base of my house, then I also connect the water pipes and bath/shower to the PEN.

From the PEN i take the Neutral trough the Wh meter, trough a.. hmm.. it's called "lekastraumsrofi" in icelandic, can't really find the word.. ahh "Earth Leakage Circuit Breaker" then into the N-connector for that ELCB.

Then every electric circuit (let's say my bedroom is on circuit 1) get 3 wires into the electric box. Live goes into the circuit breaker, Neutral goes into the Neutral connecting bracket and the ground goes into the PEN ground bracket.

So, when I get to the bedroom, let's say there are 2 lights in the ceiling of my bedroom, the pipe from the electric box goes into the mounting box(word?!?) and from there into the mounting box, over the second light.

Then from each mounting box there are pipes down into the walls for outlets and switches.

Lets say on the wall by the door you have a light switch, and an outlet in the same height (110cm), then below (at 20cm) there are 2 more outlets.

So, If i trace the ground wire from the second floor outlet to ground there is

There's a wire from the earth screw on the second outlet, that goes under the screw in the outlet next to it. From that same screw the wire goes through a pipe and into the earth screw on the outlet by the switch, then from that screw it goes into the mounting box above the light from the ceiling, there it goes into a connector with all the other ground wires from other outlets in the same room, and a wire running from that connector into the electric box, connecting it to the PEN.

So, is this star grounding ? if not, then how is star grounding, and if it is, how is any other type of grounding ?

sorry I don't have all the electric-related words I need, so I sometimes had go guess.

[Speedskater]

The real difficulty is the "grounding" has two different meanings and sometimes both apply at the same time.
Grounding:
a) Connecting to a common point or to a common reference.
b) Connecting to good old mother earth.

Item (b) has more to do with safety from thunder & lightning and electrical power problems.

Star Ground = Running a short wire from each item (that needs to be grounded) to a common point then running a single wire from that point to Ground.

When star grounding only connect your A/V equipment to the A/V star ground.