There are several classifications of sans serif fonts. The Helvetica font is one of the grotesque or grotesk sans serif fonts. It may also be classified further as neo-grotesque to differentiate it and its contemporaries from earlier grotesque fonts. It was based on Haas Grotesk and similar sans serifs which were themselves based on or inspired by Akzidenz-Grotesk, one of the first really successful sans serif fonts.
Helvetica is a registered trademark of Linotype-Hell AG and/or its subsidiaries.
From the Linotype site: "Helvetica is a Trademark of Heidelberger Druckmaschinen AG, which may be registered in certain jurisdictions, exclusively licensed through Linotype Library GmbH, a fully owned subsidiary of Heidelberger Druckmaschinen AG."
For more on the history of the Helvetica font see:
Eye Magazine 63: It may be the world’s most popular sans, but Helvetica has many deficiencies – not least its lack of real italics by Martin Majoor
Linotype: About Helvetica® Font Family ... by Linotype Design Studio


