Subdivisions of Helsinki

The city of Helsinki, the capital of Finland, can be divided into various sorts of subdivisions. Helsinki is divided into three major areas: Helsinki Downtown (, ), North Helsinki (, ) and East Helsinki (, ). The subdivisions include neighbourhoods, districts, major districts and postal code areas. The plethora of different official ways to divide the city is a source of some confusion to the inhabitants, as different kinds of subdivisions often share similar or identical names. 
Neighbourhoods.
Helsinki consists of 60 neighbourhoods ("kaupunginosa" in Finnish; "stadsdel" in Swedish). The division into neighbourhoods is the official division created by the city council and used for city planning and other similar purposes. Most of the neighbourhoods have existed since the 19th century as numbered parts of the city, and official names were assigned to them in 1959. Five neighbourhoods (numbers 55 – 59) were annexed on 1 January 2009.
Today, each neighbourhood is identified by both a two-digit number between 01 and 59 and an official name in both Finnish and Swedish (in some cases they may be identical). In addition, there is an unnumbered neighbourhood called Aluemeri that consists essentially only of outer coastal water that doesn't reach to the coast. Neighbourhoods are further divided into quarters ("osa-alue") and sectors ("pienalue"), numbered with three and four digits respectively. Sectors divide further into individual blocks and properties.
List of Helsinki neighbourhoods.
Finnish names first and the Swedish names in brackets. This due to the bilinguality of Finland and Helsinki.
Districts.
In addition to the neighbourhood division, which exists for city planning purposes, the city is also divided into 34 districts ("peruspiiri", "distrikt") to facilitate the coordination of public services. The districts, which may comprise several neighbourhoods, are organised into seven major districts ("suurpiiri", "stordistrikt"). Different quarters of a neighbourhood may belong to different districts, but individual quarters are never divided between neighbourhoods.
The district division was created by a decision of the city council on 13 December 1982, when the number of different subdivisions used by different municipal departments was seen as confusing and problematic. Before the reform, in 1980, there were 101 different divisions used by the departments, of which only 17 corresponded to the official neighbourhood division. The new districts came to use within all providers of public services by 1986.
Other subdivisions.
Helsinki is also often unofficially divided into four distinct geographic areas. These have no absolute definitions, but they are roughly as follows.
The city is also divided into postal code areas numbered between 10 and 99. Postal codes for private residences in Helsinki have the form "00xx0", where the initial '00' shows that the postal code is located in Helsinki, the next two digits show the postal code area, and the final zero indicates that the code is for a private residence (post offices use the number one, and other numbers are set aside for large businesses that have their own postal codes). "(See also Postal codes in Finland.)"