Graphical Mode vs Console Mode
There are two interfaces available in Thermo‑Calc: Graphical Mode with a graphical user interface (GUI) and Console Mode, which uses a command line interface. Thermo‑Calc and the Diffusion Module (DICTRA) are available in both modes, and all other Add-on Modules are only available in Graphical Mode.
If you are a new user, Graphical Mode is a good way to learn how to work with Thermo‑Calc. Depending on what you want to simulate, in some cases Console Mode can have more functionality but until you are comfortable with the concepts, it is recommended you start in Graphical Mode, and for all new Add-on Modules, these are only available in Graphical Mode.
In Graphical Mode calculations are set up, carried out, and visualized as part of a project. The steps in the project are performed with activities. There are templates and a Wizard available to guide you through the process of defining the project. See Getting Started Links and Templates.
In Console Mode you work with modules, which are managed using commands typed at a prompt. Some modules, called response-driven modules, ask you a series of questions that typically take you through the process of defining your system, setting calculation conditions, performing calculations and plotting the results.

The first time you open Thermo‑Calc, it defaults to Graphical Mode. For any future instance it defaults to the last mode used.
Along the top of the GUI is the Graphical Mode Toolbar where you switch between modes.
In Console Mode, except for the Switch to Graphical Mode button, the toolbar is not used.

See Menu, Toolbar, and Keyboard Shortcuts for information about the Tools, Window, and Help menus, which are available in both modes.

The file extensions are different based on the mode you are in. In Console Mode the extensions are also based on whether you are working with Thermo-Calc or the Diffusion Module (DICTRA).
In Graphical Mode, the Thermo‑Calc project files have the extension *.tcu
. This includes the examples for the Add-on Modules.
In Console Mode, Thermo-Calc macro files have a *.TCM
extension and the Diffusion Module (DICTRA) file extension is *.DCM
. In addition to macro files in Console Mode the are also Log files and Workspace files, which also differ.

The two modes can be run simultaneously, but there is no communication between them. What you do in Graphical Mode does not affect the state of the Console Mode session and vice versa. One exception is the plot settings.

Although many calculations can be done in either mode, data optimization (i.e. PARROT) and thermodynamic or kinetic assessments (i.e. custom database development) are only available in Console Mode or using an SDK such as TC‑Python.