Simply so, what is the difference between expression of hope and wish?

In a nutshell, hope mainly expresses a desire that is possible or likely to happen. Wish usually expresses a desire that is impossible or unlikely to happen.

Likewise, what is wish and hope? The difference between “hope†and “wish†is that “hope†is backed by a reasonable confidence about the desire. We hope for things that are possible and likely to happen or be achieved. “Wish†is used during desperate events (i.e. one has a deep longing for something with a slim possibility of happening).

Then, what is the difference between hoping and wishing?

Wishing is feeling or expressing a strong desire for something that is not easily attainable. It's like wishing to win the lottery but you don't buy a ticket. Hoping is to look forward with desire and reasonable confidence that something can happen.

When should we use the expression hope?

We use 'hope' to talk about things in the present or future that we think have a good chance of happening. On the other hand, we use 'wish' to talk about things that are impossible or unlikely. See more about 'wish' here.