WordPress provides an option where we can change its default link URL with a search engine friendly URL. For this, you do not need to install any wordpress plugin.
To change this default wordpress URL, login into your wordpress admin area. Navigate to settings tab in left side bar. Then Select the 7th option called Permalinks. Once you have opened Permalinks Setting page, you will few options like the following screenshot.
Detail Tutorial on WordPress Permalinks
By default the first checkbox will be selected. This Permalink structure in not good for SEO because the URL will not contain any keywords so you will not get more traffic from search engines.
Second and third checkbox is similar wordpress permalink structure. The only difference is, in first case you will get year/month/date/post-title but in second case date will not be shown in the URL. You can choose any of these two.
Fourth Checkbox Option is Numeric which will show you numeric number in the URLs and it is generated automatically.
Last one is Custom Structure where you can define your own URL structure like if you want to give only titlename and then html extension or just titlename.
You can select one of these check box to make the URL Search Engine Friendly.
Caution: Do not change the setting once you have defined the permalink URL and written posts. Just do this setting in the starting phase of blog because if you will changed your permalink structure and will make it to new custom permalink then your old link pages will show 404 error.