What is the difference between 'one card' deck building and 'pack' deck building?
I am not familiar with those terms.
Star Wars LCG has "pod" deckbuilding, in that you have sets of cards to choose from instead of individual single cards.
A Star Wars LCG deck consists of 10 defined sets of cards (most sets can be included twice), 5 cards in the player deck and 1 card in the objective deck.
The difference in deck construction is that it makes deck building simpler (although it's not easier, because a minor tweak of inclusion of one set over another impacts 1/10th of the player deck).
It changes how the game plays because you can have exact player knowledge of an opponents deck over time.