Drupal is great for SEO but it does not come straight out of the box. Drupal has about a dozen modules which will assist with SEO. These need to be installed setup and configured. Once this is done this is the starting point for your SEO journey. Keywords need to be established and content needs to be created with good URLs and the right density of keywords and links to create good onsite SEO.
Creating meta data (which is increasingly less important for Google) can be done in 1 of 2 main ways depending on how you are presenting your data. Meta data can either be linked to nodes or be independent and constructed based on the web pages URL. There are pros and cons with each approach which I will not go into here as it will take up the whole webpage.
Drupal will automatically create internal links to data if your website is dynamically constructed. These links can often be tweaked and quite dramatically improved.
Off site links use to be the major 'make or break' aspect when it came to good SEO in a crowded search area. But even these have had a major shake up at Google over the last 18 months. Google is now much more fussy at what is it considers to be a good external link. Finally one of the biggest changes affecting a websites page rank status on Google is Social Media activity. Google is increasingly looking at this as a way of gaining an insight into the importance of a website as a 'brand'. It looks at how interested real human beings are in this 'brand' on a day to day basis.
As a final foot note on SEO, Google is not the only search engine. However it is more widly used in Western coutries than that the rest of its competitors put together. If you apply your Google techniques to other Search Engines succes on them will quickly follow.