Parasolid files, typically with extensions like .x_t (text) or .x_b (binary), are a common format for representing 3D solid models. They are the native file format for the Parasolid geometric modeling kernel, a widely used kernel in various CAD/CAM/CAE software applications. These files store the geometric and topological information of a 3D object, including its surfaces, edges, vertices, and relationships between them. The .x_t format is a human-readable ASCII text format, making it easier to inspect and potentially edit (though not recommended for complex models). The .x_b format is a binary format, which is more compact and efficient for storage and transfer of large models. Parasolid files are often used for exchanging 3D model data between different CAD systems, as the Parasolid kernel is licensed to many software vendors. They are crucial for interoperability in the product development process, allowing engineers and designers to share and collaborate on 3D models regardless of the specific CAD software they use. The files contain precise geometric data, enabling accurate simulations, manufacturing processes, and visualization.