Adobe Photoshop is a raster graphics editor developed and published by Adobe Systems for Windows and OS X.
Photoshop was created in 1988 by Thomas and John Knoll. Since then, it has become the de facto industry standard in raster graphics editing, such that the word “Photoshop” has become a verb as in “to Photoshop an image,” “photo shopping” and “Photoshop contest”, though Adobe discourages such use. It can edit and compose raster images in multiple layers and supports masks, alpha compositing and several color models including RGB, CMYK, Lab color space, spot color and duotone. Photoshop has vast support for graphic file formats but also uses its own PSD and PSB file formats which support all the aforementioned features. In addition to raster graphics, it has limited abilities to edit or render text, vector graphics (especially through clipping path), 3D graphics and video.
Today Photoshop is one of the world’s most popular photo editing software. Good computer skills are required to learn Photoshop. This course has covered basic and essential of Photoshop. We have covered topics like Interface of Photoshop, understanding panels, creating new document, the menu bar, toolbar, setting preference, rulers and guide, making selection, locking merging and copying layers, blending modes etc.
So this is about basics of. There are many versions of Photoshop available. Each latest version provides new features. Depending on which version you are using feature and techniques differs. You can get latest guide and helps about Photoshop from https://helpx.adobe.com/photoshop/tutorials.html