What is the difference between it is broken and it has been broken please?
When I say something is broken, broken is used as an adjective. I'm describing the state of the thing and I'm not interested in the action that led to this state. For all I know it could have got broken without human intervention through decomposition, old age, etc. And it does not say how long it's been in that state, it could be minutes, hours, years, etc.
My CD player is broken.
It's a plain statement.
If I say something "has been broken" (present perfect, passive), I focus on the action and not on the object. It helps me specify one or several aspects of this action.
My CD player has been broken for a week now.
This last sentence focuses on how long it has been in that state.
I love this vase, unfortunately it has been broken twice and next time I don't know if I'll be able to mend it.
This last sentence focuses on the repetition of the action.
I can't listen to my CDs now that my CD player has been broken.
When I say this last sentence, although I do not name anyone I imply that the CD player got broken through human intervention. I could even be more specific and add who caused this to happen.
I can't listen to my CDs now that my CD player has been broken by my brother.
So your choice of one or the other will entirely depend on context, on what you want to say.
First of all, the sentence "it is broken" is in the "Present passive voice" and the second one is in the "Present perfect passive voice". And the main difference is that you may use the first sentence if the action is happening at the moment or not a long time ago. Whereas when you use the second one, the range of time in which the action may have happened seems longer.
"-Oh, you dropped the glass!
-Oh, no. It's broken." (It is broken)
"-We've not lived here for ages.
- Look at this glass. It's been broken." (You have no idea when the glass has been broken) (It has been broken)
BTW, as usual, there are many ways to say a single sentence in English, so sometimes you can use either of the sentences interchangeably.
You can use both. But "it has been broken" especially refers to the recent time period i.e. a finished action with a result in the present (focus on result) (it is a present perfect tense)