Government 
Switzerland's 1848 constitution made it into a federal state, giving it a central authority that counterbalanced and limited the power of the individual cantons. Some areas, such as foreign policy, are now solely in the hands of the central government. The cantons no longer have the right to secede.
The constitution was designed to balance as fairly as possible the interests of the state as a whole with the interests of the individual cantons.
For historical reasons, Switzerland's official name is still the "Helvetic Confederation" (in Latin: Confoederatio Helvetica) from which the country's international abbreviation, CH, is derived. However, this is in fact a misnomer: a confederation is an alliance of autonomous entities. Since 1848 Switzerland has been a federation: a grouping of entities with a central authority.
The word Helvetic refers to the Helvetians, one of the many Celtic tribes living in what is now Switzerland at the time of the Roman conquest.
CH: Confoederatio Helvetica
Government
Switzerland in its modern form came into being in 1848. Until that time, Switzerland was not a real state, but a loose alliance of autonomous cantons whose degree of cooperation with each other varied from one period to another. Before 1848 the cantons were free to secede from the confederation if they wanted to.