The **`user-select` property** is used to define how text selection should happen.

We can set two values to change the text selection property: 
1. `none` -- Disables the text selection 
2. `all` -- Selects all the content of the element with a single click.

<html>
 <head>
 </head>
 <body>
 This text cannot be selected 
 This text can be selected on clicking once
 </body>
</html>

p{
    font-size: 30px;
}
.no-select {
    user-select: none;
}
.select-all{
    user-select: all;
}

codemirror


* If the parent's user-select is set to `all` and the child doesn't have user-select, then all contents are selected when clicking the child or parent.

* If the parent's user-select is set to `none` and the child doesn't have user-select, then the child contents cannot be selected.

* If the child's user-select is set to `all` and the parent doesn't have user-select, then the parent will not click on the child.

* If the child's user-select is set to `none` and the parent's user-select is set to `all`, then the child will not click the parent. 

<html>
 <head>
 </head>
 <body>
 Parent with user select all (child)
 Parent Not get selected on clicking child (child select all).... 
 Parent will select on single click (But child remains unselectable) ....
 Parent & child Cannot be selected <span"> (child with no user-select property) ....
 </body>
</html>

p{
    font-size: 20px;
}
span{
    color: red;
}
.select-all{
    user-select: all;
}

.no-select {
    user-select: none;
}


---
If an element doesn't have a user-select property, the default value is set to `auto`. The `auto` property means: 

* For the `::before` and `::after` pseudo-elements, the value of user-select is `none`.

* For the editable elements, like `input textarea`, the user-select value is contained.

* The user-select property of the parent is used.
* Other than this, the user-select value is `text`.

What is the user-select property in CSS?

The user-select property in CSS controls text selection behavior with values like none, all, and auto.