What is the difference Japanese particle に-ni and で-de

As you may know, there are some meanings the particle ni and de.
However, I will explain them very simply and focus on the 場所 + で.

What is the difference に and で?

The particle ni に

に is used for the direction or existence things.

• Direction
  わたしは、学校に（へ）　行きます。
  来週末、東京に（へ）　行きます。
  ここに、コップをおいてください。
  
• Existence things
  わたしは、京都に　住んでいます。
  ここに、コップがあります。
  公園に、こどもがいます。

Even advance class, Some often make a mistake the way of using ni and de.

Please pay more attention to the existence things.

The particle de で

The particle de is often used with action.

• Location
  わたしは、カフェで　コーヒーを　飲みます。
  ここで、会いましょう。
  子どもたちは、公園で　遊びます。

So, You can’t say

わたしは、京都で　住んでいます。incorrect.
*In the very few case, you can. but normally, no.
ここで、コップがあります。incorrect.
公園で、こどもがいます。incorrect.

まとめ

I focus on the place + de pattern, this time.

Now you can explain the difference those sentences below, can’ you?

ここに、コップをおいてください。

ここで、コップをおいてください。

Both are correct, but the meaning is different.

The first one means “to here”*direction
This is kind of like this, “Please put the cup from there to here.” / “Please put the cup here, not there”
It focuses more on the position.

The second one means “in/at here”*location
This sentence focus on the action.
You are holding the cup, and you have to put it here.
The place you do that is here.