This Open icon is made in Material Design style developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 4,400 icons, all in the same style and quality.
The open folder icon for pc. Manila folder that's slightly open, where files are stored. The tab is at the top left in this variant. This is what people double click to get to their information on computers.