If you a new to SEO, you probably would not have known about the title attribute until someone more experienced pointed out that it is a good practice to use it.
Title attribute tells the browser to pop up a little window when a user mouse over to the object that contains the attribute. Based on many articles that haven been posted on Moz.com, it used to have some SEO value but now a days it is just like meta description tag and the only thing it does is increase CTR (Click Through Rate) if done right.
On the other hand, as more people using mobile device to browse sites, title attribute may become obsolete as the popup window hinders the usability of the site.
The ideal usage of Title attribute is with images. As many SEO professionals already know, adding as ALT attribute to an image is a standard practice, considering it also has some significant SEO effect, but from user interface point of view, the text will not show up unless the image is not delivered to the end user. Title attribute can be used to enhance the communication with the end user (in case they do not want to read the text and just want to skim through the images), or when the image is serving as a link (to example what to expect at the other end of the link).
The bottom line is, it may be a grandfather SEO technique and it may not provide any SEO juice any more, but depending on the usage, it could still provide a substantial value to your on page SEO efforts.
Further Reading and Reference