A:

Difference 1: link is XHTML tag, in addition to loading CSS, can also be used to define RSS, define rel connection attributes, etc. @import is provided by CSS and can only be used to load CSS.

Difference 2: when link references CSS, the page is loaded at the same time; @import requires the page to be fully loaded and later loaded.

Difference 3: link is XHTML tag, no compatibility problem; @import was introduced in CSS2.1 and is not supported by browsers with lower versions (IE5 and below).

Difference 4: link supports using Javascript to control the DOM to change styles; @import is not supported.

2:

Essentially, both of these are for loading CSS files, but there are subtle differences

The difference between ancestors. Link belongs to the XHTML tag, and @import is entirely a way of providing CSS.

Link tags can do a lot of other things besides loading CSS, such as defining RSS, defining rel connection properties, etc. @import can only load CSS.

2. Differences in loading order. When a page is loaded (that is, viewed by the viewer), the CSS referenced by link is loaded at the same time, while the CSS referenced by @import is loaded when the page is all downloaded. So sometimes when you're browsing a CSS page loaded with @import, you start off with no style (just flicker) and it's obvious when the network is slow.

3 compatibility differences. Since @import is proposed by CSS2.1, old browsers do not support it. Only those above IE5 can recognize @import, while the link tag does not have this problem.

4 use dom to control style differences. When using javascript to control the dom to change the style, you can only use the link tag, because @import is not something that the dom can control.

内联引用 CSS。可灵巧应用样式於各标签中。方便于编写代码时的使用。没有整 篇文件的“统一性”，在需要修改某样式的时候也变的比较困难。

内部引用 CSS 将样式规则写在<STYLE>...</STYLE>标签之中。

外部引用 link 标签引用 CSS 将样式规则写在.css 的样式文件中，再以标 签引入。这样引入该 css 样式表文件以后，就可以直接套用该样式档案中所制定的样 式了。

外部引用 @import 引用 CSS 跟 link 方法很像，但必须放在<STYLE>..</STYLE> 中： <STYLE TYPE="text/css"> </STYLE>可以灵活的引入 css 文件对 xhtml 元素进行控制。有时候也用来 编写某些 css hack。这种方法的缺点：在个别文件或元素的灵活度不足老祖宗的差 别。link 属于 XHTML 标签，而@import 完全是 CSS 提供的一种方式。

加载顺序的差别。当一个页面被加载的时候（就是被浏览者浏览的时候），link 引用的 CSS 会同时被加 载，而@import 引用的 CSS 会等到页面全部被下载完再被加 载。

兼容性的差别。由于@import 是 CSS2.1 提出的所以老的浏览器不支持，@import 只有在 IE5 以上的才能识别，而 link 标签无此问题。

使用 dom 控制样式时的差别。当使用 javascript 控制 dom 去改变样式的时 候，只能使用 link 标签，因为@import 不是 dom 可以控制的。