The -d option in Curl stands for "data". It is used to send data in a POST request to a server. This option tells Curl that you are going to send data to the server and the data will follow after the -d option.
Typically, the -d option is used when you want to provide data to the server in the form of key-value pairs. The data is sent in the HTTP body of the POST request. This is a common way to send data when you are working with forms on the web.
Here's an example of how to use the -d option in Curl:
curl -d "key1=value1&key2=value2" http://example.com
In this example, Curl sends a POST request to http://example.com with the data key1=value1&key2=value2.
You can also send data as a JSON object using the -d option. To do this, you need to set the Content-Type header to application/json using the -H option in Curl:
curl -d '{"key1":"value1", "key2":"value2"}' -H 'Content-Type: application/json' http://example.com
In this example, Curl sends a POST request to http://example.com with the JSON data {"key1":"value1", "key2":"value2"}.
Remember that if you are sending a JSON object with the -d option, you need to set the Content-Type header to application/json. Otherwise, the server might not be able to correctly process the data you are sending.
