# Introduction to the CLI application
To begin, open the terminal application.
On Windows, right-click the Start icon or press Windows+X. Then, select [Terminal](https://learn.microsoft.com/en-us/windows/terminal/).
On macOS, open Finder, then select Applications, Utilities, then [Terminal](https://support.apple.com/en-us/guide/terminal/apd5265185d-f365-44cb-8b09-71a064a42125/mac).
On Linux, open Applications. Select System, then Terminal. Or, search for "terminal".
The terminal application will then present a command line interface (CLI). On Windows, this is [PowerShell](https://learn.microsoft.com/en-us/powershell/). On macOS or Linux, this is typically [Bash shell](https://www.gnu.org/software/bash/manual/bash.html).
If you have the application is under the search path (PATH environment variable), to run it, type:
```sh
warcat
```
and press enter.
Or, enter the location of the executable directly. For example (Windows):
```powershell
.\Downloads\warcat.exe
```
macOS/Linux:
```sh
./Downloads/warcat
```
and press enter.
If it is successful, the warcat application will display help information.
Entering
```sh
warcat help
```
will also show a list of commands and options. `help` is known as an argument that is passed to the program.
For example using the `list` command:
```sh
warcat list --input my_warc_file.warc.gz
```
The above command has 3 arguments to the program:
1. `list` is the command.
2. `--input` is an option. It starts with 2 hyphens. This specifies that the program should accept an input filename.
3. `my_warc_file.warc.gz` is a value to the `input` option.
If an option value has spaces or special symbols, put quotation marks:
```sh
warcat list --input "My WARC File (Copy).warc.gz"
```
Option values can also be specified by a `=` character if it helps with clarity:
```sh
warcat list --input=my_warc_file.warc.gz
warcat list --input="My WARC File (Copy).warc.gz"
```
Note that some options don't take a value. These options are also known as flags (as in boolean true/false):
```sh
warcat --quiet
```
If you need help in a command, enter something like:
```sh
warcat help list
```