How did trench warfare work in WW1?

What is trench warfare? 

Were they go to a battle field and  2 or more countries dig
holes on each side and put boards in the holes and make
stairs. Then they fight to the end and millions of people
died in trench warfare.  

In trench warfare there were a lot of rats so they put food
in barrels and when the rats came they would shoot them.
And if you got trench foot it is like a infection. But it feels
like a painful condition of the feet caused by long
immersion in cold water or mud and marked by blackening
of your toes. 

It is estimated that there were about 2,490 kilometre of
trench lines dug during World War 1. Most trenches were
between 1-2 metres wide and 3 metres deep. Trenches
weren't dug in straight lines in WW 1 but  trenches were
built as  zigzag or in pattern with many different levels
along the lines.

Around 8.5 million to 12 million people died during the
war. And more than 100 countries went to the trench
warfare. Including  Germany, Austria Hungary, Bulgaria
and the Ottoman Empire (the Central Powers) fought
against Great Britain, France, Russia, Italy, Romania,
Japan and the United States. 

In conclusion this is how I think trench warfare worked in
WW 1.

By Carla-Rose