multi-party
it is not federalism as federalism only has 43 of 123 nations
multi-party
base-10 number system
Arabic
No, they are not.
no because its not common in the world today.
The two most common party systems in English-speaking countries are the two-party system, where two major parties dominate the political landscape (e.g., Democrats and Republicans in the U.S., Conservatives and Labour in the UK), and the multi-party system, where several parties compete for power and representation (e.g., Canada, Australia).
unitary system
Zero
not at all not in the world since 1940!
very very bad system of the world
One party system has never served the common good anywhere in this world, because power and authority pollutes the party ranks that much easily and soon. So for a start, a two party system is desirable. But when we view the political history of modern nations, i.e. nations whose political prominence was decided after the Second World War, we see that sooner or later both the parties follow the same line of administration and have been reflecting and adopting more or less the same inclinations and policies internally and externally. That is why people feel betrayed each time and governments change alternatively. The only way to safeguard people's interests in the administration so is a multi party system in the present circumstances. Not that it too won't fail, but it certainly will limit any party's excessive involvement in the administration, by making each party vulnerable. Some may argue that this multi party system will hinder governments from taking and implementing firm decisions, but good decisions that serve common good can remain firm anyway.