next/link

• with links created using a tag, request is sent to server to load the page. But with next/link, client side navigation happens. So navigation is faster.
• With traditional links, preloading does not happen. With next/link, urls are preloaded.

next/image

• Images are optimized for different device sizes and resolutions. Image compression may be done.
• Lazy loading is supported meaning images are loadded only when they enter viewport. So no need to use any third party library to do this.
• Image Formats - Next.js analyzes the source image and automatically selects the most appropriate image format for each browser, such as JPEG, PNG, or WebP.
• Image Placeholder: Next.js generates a blur-up placeholder or a solid color placeholder for each image. The placeholder is displayed while the actual image is being loaded, providing a smooth and visually pleasing experience during the loading process.