Mockup PSD refers to a Photoshop Document (PSD) file that contains a pre-designed template or layout for creating mockups. These PSD files are often used by designers to showcase their designs or concepts in a realistic and visually appealing way. Mockup PSDs can be found for various products, such as smartphones, laptops, stationery, packaging, apparel, and more.

Mockup PSD files typically consist of multiple layers, including smart objects, which allow you to easily insert your design or artwork into the predefined placeholders. By replacing the smart object layer with your own content, you can quickly visualize how your design would look in a real-world context without starting from scratch.

To use a mockup PSD file, you would typically follow these steps:

1. Find and download a mockup PSD file suitable for your project.
2. Open the PSD file in Adobe Photoshop.
3. Identify the smart object layers within the PSD file that are intended for placing your design.
4. Double-click on the smart object layer to open a new window or panel.
5. In the new window, insert your design or artwork. This could be a logo, a graphic, or any other visual element.
6. After adding your design, save the changes and close the smart object window.
7. The mockup PSD file will now display your design in the predefined template or layout.
8. Customize additional elements, such as colors, backgrounds, or textures, if desired.
9. Finally, save your modified PSD file or export it as a different file format, such as JPEG or PNG, depending on your needs.

Mockup PSD files offer a convenient and efficient way to create high-quality mockups, enabling designers to present their work in a visually appealing manner. They save time and effort by providing pre-designed templates that can be easily customized to showcase designs in realistic settings.