Blender is a popular open-source 3D modeling software that uses .blend files to store 3D models, scenes, and animations. To open a blend file, follow these steps: 1. Launch the Blender software on your computer. 2. Once the software is open, go to the 'File' menu at the top left corner of the screen. 3. Click on 'Open' from the drop-down menu. 4. Navigate to the location where your .blend file is saved on your computer. 5. Select the .blend file and click 'Open' to load it into Blender. 6. The blend file will now open in Blender, allowing you to view and edit the 3D model, scene, or animation. Remember to save your work regularly to avoid losing any changes. Opening a blend file in Blender is straightforward and allows you to work on your 3D projects with ease.