Grotesque was the first form of sans serif type. It appeared in the early 19th Century, and had a somewhat irregular and awkward form (hence the name). The more refined evolution of this style, popular in the mid 20th century, became known as Neo-grotesque.
Examples of Neo-grotesque typefaces include Space Grotesk and Work Sans.
However, it’s important to note that—like any historical classification—Grotesque typefaces that fit this style don’t necessarily come from this period in history.