What is a multi-party system?

What is a multi-party system? Explain merits and demerits of multi-party system.

Multi-Party System If several parties compete for power and more than two parties have a reasonable chance of coming to power either on their own strength or in alliance with others, we call it a multi-party system.
Merits
(i) Multi-party system allows a variety of interests and opinions to enjoy political representation.
(ii) Here people have an opportunity to make a choice between several candidates.
Demerits
(i) This system often appears very messy.
(ii) This system sometimes leads to political instability.