If someone want to have a quick look your blog, archive page can help them do it.

To set up a separate archive index in a way that plays with the Version 1.5 theme system, you’ll need to create it as a Page, and assign it a special template.

Here is how to create a custom archive page in WordPress just like the one you see on our blog. 

Following these 5 steps, you can quickly create a archive page in your wordpress blog.

1. Go to the current theme folder of your WordPress installation (wp-content/themes/*current theme*) and make sure you don’t already have archives.php in the folder

2. Create a new file called archives.php (or whatever file name you want to give)

3. Copy and paste the following code into the new file and upload it to your current theme folder (wp-content/themes/*current theme*)

4. …

More details here.