The file extension SVGZ identifies svg files that have been compressed with GZIP.
SVG is a standard 2D vector graphics format developed by the World Wide Web Consortium (W3C) for displaying vector graphics on the Internet. The so-called Scalabe Vector Graphics Format (scalable vector graphics) describes images in a text format based on XML. Even normal pictures can be embedded.
SVGZ files can be used directly as a graphic format (eg for data exchange) or embedded in a web page. Most new browsers can display SVGZ graphics, but Microsoft Internet Explorer 9 requires a plugin for this.
In addition to the current format version SVG 1.1, there is also an SVG Tiny 1.2, which is geared to the application in mobile devices.