Veda is sanskrit and means "knowledge"
The Vedas are a composition of complete transcendental knowledge. What makes them special is, that they were not created by man, but by god. Transcendental means, they are not of this material world and represent the absolute truth, which cannot be affected by material circumstances like time, this means the vedas cover all knowledge of past, present and future.
At the beginning of the creation of this world Krsna tought Brahma, the creator of our universe the Vedas. Brahma is the first material being or a mortal being, but the Vedas originate from Krsna and Krsna is not a material being, which makes the Vedas transcendental.
The purpose of the Vedas is to be like an instruction manual for the creation, they cover all possible fields of science, most importantly how to get out of this world and back to god, which is the primary function of the Vedas.
Vedic wisdom can only be learned through hearing from a true spiritual master, who is a successor of the Brahma. Krsna spoke the Vedas to Brahma and Brahma spoke them to his disciple and that disciple gave it to his disciple and so on, from the beginning of creation till now. So it is most important to only hear the Vedas from this disciple line, otherwise the true meaning of the Vedas gets lost. Since man is imperfect any manipulation of the Vedas through man makes them imperfect as well, this is why the true meaning of the Vedas can only be learned through the true disciple line which just preserve the Vedas as they originally were.
The last disciple was Srila Prabhupada and the line of disciples is now broken, so he is the last author from who you will get the true meaning and in the future it may be lost, this is why it is so important to preserve the vedic knowledge.