The Senedd has 60 elected members.
Each voter in elections to the Senedd has two votes, used in a voting system known as the Additional Member System. The system is a form of proportional representation.
The first vote is used to elect a constituency Senedd Member on the basis of the traditional 'first past the post' electoral system, similar to a UK Parliamentary election. The Senedd constituencies are coterminous with UK Parliamentary constituencies and this results in the election of 40 constituency Assembly members.
The second vote is used to elect regional Senedd Members - four Senedd Members are elected from each of the five electoral regions across Wales. These regions are North Wales, Mid and West Wales, South Wales West, South Wales Central, and South Wales East.
Using their second vote, electors vote for an independent candidate or a political party in a 'closed list' system. In relation to political parties, ballot papers show the list of named candidates nominated by each political party and successfully elected candidates are drawn in order from the top of the relevant party list. This results in the election of 20 regional Senedd Members.