What is tether?

English Language Learners Definition of tether. (Entry 1 of 2) : a rope or chain that is used to tie an animal to a post, wall, etc., so that it will stay in a particular area.

What is the difference between all this makes and all these make?

All this makes or All these make ? All these is not an idiom and is not used in the same way as all this. It is better to say all these things or all these features or all these reasons. In your example, all this is more appropriate. All this can be used to refer to multiple things, even though this implies something singular.

What does all this mean?

In your example, all this is more appropriate. All this can be used to refer to multiple things, even though this implies something singular. When you use all this, think of it as meaning all this stuff. The mobile phone is cheap. It has a good battery. It has front and rear cameras.

What is the difference between this and these?

This is for singular whereas These is for plural. Since you are referring to both front and rear camera it is plural. Other than that, there are two cameras: front and rear. So you should write cameras instead of camera. Your final sentence would be: That mobile is cheap. It has front and rear cameras. All these make it a good phone.