Is there a difference between Tagalog and Filipino?

Filipino or Tagalog? Is there really a difference? Sometimes, we just shrug this question off. It's easy to say these two don't have a difference since native speakers of these languages will not be strangers when they talk. They will understand each other completely.
But technical translations demand more literal transfers. Consequently whether to use Filipino or Tagalog becomes a conscious question. When source words are without exact equivalents in Tagalog, here is where Filipino becomes useful. In a sense, one often resorts to using Filipino when "pure Tagalog" expressions can't be found. A translation therefore can be a mixture of Filipino or Tagalog, assuming that there is a clear line that distinguishes them from each other.

Tagalog is not a dialect but a major language in the Philippines. Within the Tagalog region, there are many dialects such as the variations found in Nueva Ecija, Bulacan, Mindoro, Palawan, Quezon, Rizal and Batangas provinces. Ninety percent of native Tagalog speakers are born and bred and grew up in these provinces.

Filipino is based on Tagalog. Without Tagalog, I doubt if there will ever be a clear identification of the Filipino language. On second thought, maybe, Filipino will be based on Cebuano, or Ilocano, or Bicolano, or Ilongo which are also major languages. Some Cebuanos are sometimes jealous because majority of the so-called Filipino words and expressions are actually Tagalog.