Difference between 内側 and 中


I was wondering what the difference is between 内側 and 中 as I understand both
mean "inside". However, there are situations when we can use one and not the
other.




The basic concept is: ![enter image description
here](https://i.stack.imgur.com/2LPMB.png)

**内側** means that spaces are divided by something like fence, and you're
standing on the inside ground, while **中** is like that there's a vessel and
you're inside it.

The interpretation of `Xの内側` and `Xの中` is different regarding the `X`. In the
former, `X` indicates **boundary** , while in the latter, `X` is
**container**. If you say `Xの中` when `X` is something with inner room, then
whoever in there is likely to be in that space, but when `X` is a filled
material, then they're likely to be packed within it.

* * *

**Random examples taken from Google image search:**

They are thought to be in **ガラスの内側** but not ガラスの中:

![enter image description here](https://i.stack.imgur.com/sgFHR.jpg)

while he is thought to be in **ガラスの内側** or **ガラスの中** :

![enter image description here](https://i.stack.imgur.com/SpOCa.jpg)

and they are thought to be in **ガラスの中** but not ガラスの内側:  
(well, these are actually ice cubes but never mind)

![enter image description here](https://i.stack.imgur.com/pEkGj.jpg)

* * *

**Extra**  
There's another (mostly figurative) usage of **中** , that is you can refer
what you see through apertures such as: 絵の中, 鏡の中, 画面の中 etc.




The basic concept is: ![enter image description
here](https://i.stack.imgur.com/2LPMB.png)

**内側** means that spaces are divided by something like fence, and you're
standing on the inside ground, while **中** is like that there's a vessel and
you're inside it.

The interpretation of `Xの内側` and `Xの中` is different regarding the `X`. In the
former, `X` indicates **boundary** , while in the latter, `X` is
**container**. If you say `Xの中` when `X` is something with inner room, then
whoever in there is likely to be in that space, but when `X` is a filled
material, then they're likely to be packed within it.

* * *

**Random examples taken from Google image search:**

They are thought to be in **ガラスの内側** but not ガラスの中:

![enter image description here](https://i.stack.imgur.com/sgFHR.jpg)

while he is thought to be in **ガラスの内側** or **ガラスの中** :

![enter image description here](https://i.stack.imgur.com/SpOCa.jpg)

and they are thought to be in **ガラスの中** but not ガラスの内側:  
(well, these are actually ice cubes but never mind)

![enter image description here](https://i.stack.imgur.com/pEkGj.jpg)

* * *

**Extra**  
There's another (mostly figurative) usage of **中** , that is you can refer
what you see through apertures such as: 絵の中, 鏡の中, 画面の中 etc.

