Bootstrap 5 Grid system Setting one column width is used to set the width of a specific column, it can be applied to any column. The Auto-layout for flexbox grid columns means you can set the width of one column and the sibling columns will automatically resize around it.
Bootstrap 5 Grid system Setting one column width Class: There is no specific class for this, you .an use the col-& classes to set the width.
Syntax:
<div class="row">
<div class="col">
...
</div>
<div class="col-6">
...
</div>
<div class="col">
...
</div>
</div>
Example 1: The code in the example shows how setting only the center column's width leads the other columns to resize themselves accordingly.
<!doctype html>
<html lang="en">
<head>
<link href=
"https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/css/bootstrap.min.css"
rel="stylesheet"
integrity=
"sha384-EVSTQN3/azprG1Anm3QDgpJLIm9Nao0Yz1ztcQTwFspd3yD65VohhpuuCOmLASjC"
crossorigin="anonymous">
<script src=
"https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/js/bootstrap.bundle.min.js"
integrity=
"sha384-MrcW6ZMFYlzcLA8Nl+NtUVF0sA7MsXsP1UyJoMp4YLEuNSfAP+JcXn/tWtIaxVXM"
crossorigin="anonymous">
</script>
</head>
<body class="m-3">
<h1 class="text-success">GeeksforGeeks</h1>
<strong>BootStrap5 Grid system Setting one column width</strong>
<div class="container mt-4 text-light">
<div class="row">
<div class="col bg-success border">
Column 1
</div>
<div class="col-8 bg-success border">
Column 2
</div>
<div class="col bg-success border">
Column 3
</div>
</div>
</div>
</body>
</html>
Output:

Example 2: The code in the example shows how setting only the center column's width inside even Nested Grid also leads the other columns to resize themselves accordingly:
<!doctype html>
<html lang="en">
<head>
<link href=
"https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/css/bootstrap.min.css"
rel="stylesheet"
integrity=
"sha384-EVSTQN3/azprG1Anm3QDgpJLIm9Nao0Yz1ztcQTwFspd3yD65VohhpuuCOmLASjC"
crossorigin="anonymous">
<script src=
"https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/js/bootstrap.bundle.min.js"
integrity=
"sha384-MrcW6ZMFYlzcLA8Nl+NtUVF0sA7MsXsP1UyJoMp4YLEuNSfAP+JcXn/tWtIaxVXM"
crossorigin="anonymous">
</script>
</head>
<body class="m-3">
<h1 class="text-success">GeeksforGeeks</h1>
<strong>
BootStrap5 Grid system Setting one column width
</strong>
<div class="container text-light mt-4">
<div class="row">
<div class="col-1 bg-secondary border">
Col 1
</div>
<div class="col-1 bg-secondary border">
Col 2
</div>
<div class="col bg-secondary border">
<div class="container">
<div class="row">
<div class="col bg-success
border">
Small Col 1
</div>
<div class="col-6 bg-success
border">
Small Col 2
</div>
<div class="col bg-success
border">
Small Col 3
</div>
</div>
</div>
</div>
</div>
</div>
</body>
</html>
Output:

Reference: https://getbootstrap.com/docs/5.0/layout/grid/#setting-one-column-width