Mediators are generally thought of as people who can diffuse conflict (of different sorts) and guide people towards a cooperative solution to the issue which is dividing them.
In a typical mediation scenario, there is neither a "winner" nor a "loser".
The aim of the mediator is to find the "zone of potential agreement" in which both parties get enough of what they want for them to feel comfortable with the outcome.
A mediator's skill set is often hugely valuable across a wide range of situations, which is why there are so many sub-niches of mediation, some of which are already well established (such as corporate mediation) and some of which are only just beginning to grow (such as immigration mediation).
The issue of cultural conflict
Cultural conflict is more commonly known as "culture clash" and anyone who's ever been in a strange place has probably experienced it to some extent.
The greater the differences between a person's own culture and the culture in which they find themselves, the greater the degree of confusion they experience. At a low level, cultural conflict can be genuinely funny. In fact, there are a lot of classic comedies based on it.
At a more serious level, however, cultural conflict can be deeply traumatizing for the migrant and frustrating for locals.
The issue of assimilation
Traditionally the onus has been very much placed on the immigrant to assimilate to the country in which they find themselves rather than their host country making adaptations for them.
At least, that has generally been the official line (and often remains so today).
In reality, however, most countries have long been perfectly happy to make reasonable adaptations for immigrants, and there has long been some degree of recognition that effective assimilation requires locals to explain what is expected of an immigrant rather than just assuming that they will automatically know what "everybody else knows".
In other words, there has long been at least tacit recognition that it simply makes sense to help immigrants to assimilate as much as possible while giving them some degree of breathing space with regards to maintaining their own beliefs and practices.
Fast-moving times call for fast-acting solutions
Movement of people has been a fact of life for the entirety of human history, but the combination of modern transport and unrest around the world has resulted in there being growing numbers of people who find themselves living in places where the culture is completely alien to them and without the option to return to their old home if they find themselves unable to cope with this change.
Host countries typically have a legal duty to absorb these people (as well as a moral one) and therefore need to find effective ways to help them to assimilate as quickly as possible.
In the context of immigration situations, this means being both pragmatic enough and compassionate enough to recognize that most immigrants can only really be happy when they can find ways to show respect to their host culture without disrespecting their birth culture.
In other ways, they need to resolve their own internal conflict in order to reach an outcome with which both their "old" self and their "new" self can feel comfortable.
This is exactly the sort of situation which mediation can help to resolve.