Web Design

FeatureResponsive Web DesignAdaptive Web Design
DefinitionResponsive design automatically adjusts layout based on screen size using flexible grids and CSS media queries.Adaptive design uses multiple fixed layouts designed for specific screen sizes.
FlexibilityVery flexible — works on any screen sizeLess flexible — designed for specific devices only
LayoutOne fluid layout that changes dynamicallyMultiple static layouts (e.g., for mobile, tablet, desktop)
TechnologyUses CSS media queries, flexible grids, percentagesUses predefined breakpoints and separate layouts
DevelopmentEasier to maintain (one version of the site)More complex (multiple versions needed)

Responsive Web Design

This example shows how the layout changes from horizontal to vertical on smaller screens.

<!DOCTYPE html>
<html>
<head>
    <style>
        body {
            font-family: Arial;
        }

        .container {
            display: flex;
            flex-direction: row;
        }

        .box {
            flex: 1;
            padding: 20px;
            background-color: lightblue;
            margin: 10px;
            text-align: center;
        }

        /* Mobile view */
        @media (max-width: 768px) {
            .container {
                flex-direction: column;
            }
        }
    </style>
</head>
<body>

<div class="container">
    <div class="box">Block 1</div>
    <div class="box">Block 2</div>
    <div class="box">Block 3</div>
</div>

</body>
</html>

Adaptive Web Design

This example uses specific breakpoints and fixed widths for different devices.

<!DOCTYPE html>
<html>
<head>
    <style>
        body {
            font-family: Arial;
        }

        .container {
            width: 960px;
            margin: auto;
        }

        /* Tablet layout */
        @media (max-width: 1024px) {
            .container {
                width: 700px;
            }
        }

        /* Mobile layout */
        @media (max-width: 600px) {
            .container {
                width: 100%;
                background-color: lightgray;
            }
        }
    </style>
</head>
<body>

<div class="container">
    <h1>Adaptive Layout Example</h1>
    <p>This layout changes based on fixed screen sizes.</p>
</div>

</body>
</html>

My opinion wich is better

Responsive web design is better, it is more flexible because it works on any screen size, not just specific devices.
Adaptive design can be useful in some cases, especially when performance is important, but it requires more work and is less flexible.

My Site with adaptive design:
Link

Test on the other site (Euronics)

Mobile:
The menu on the phone has become much narrower, and the filter menu has been hidden

Tablet and pc are the same: