What type of input that should add value

[Xenxaz]

just curious about input value that is sent to backend stuff
I have researched and found that if

<input type="text" id="fname" name="fname" value="name">
<input type="text" id="lname" name="lname" value="surname">

my input will be received as fname=name&lname=surname
then what about the value of radio, dropdown, and checkboxes?

edit: for best practice

[ombasaanyona]

For Radio only the selected radio button sends its value. For example, if you have:

And the user selects “male”, the data sent to the backend will be gender=male.