What is PSD formatted files and how can they be opened?

PSD stands for PhotoShop Data file which can be opened with Photoshop or other image editing softwares that recognize psd format. There may also some online tools that opens it.

Psd files are actually image files, but these image files store editable layer and font data for later use. Therefore you can edit these texts and image layers on the image when you opened it in Photoshop.

Not every psd file store layer data. A standart single layer image may also be saved as psd format. Such files do not make much sense because of the image is uneditable like standart jpg or png files. They also might take up a lot of space because of psd format may become the file size in bytes bigger. If you've got a single layer psd file which you need to convert it into the jpg or another formats, you can use the "Save As" or "Save For Web" tabs under the "File" menu in Photoshop or use the online converter tools which can be found by googling like "psd to jpg" or "psd to ... convert".