The Hot 100 used to measure how much money was being put into the song, combining sales to the public and how often it was broadcasted (which cost a lot of money to do). Now the chart measures how many times people play the song in their house with no financial investment on their end (and includes companies being hired to jack the streaming numbers up).
The albums chart used to measure how many albums were paid for. Now it measures "album equivalent units" - again easily manipulated.
Premium streaming totals are divided by 1,250 and free streaming totals are divided by 3,750. Thus, 1,250 premium streams or 3,750 free streams from the same album is equivalent to 1 album unit.
All of those Taylor numbers are bullshit. If they had a way to track how often people were spinning songs from the Beatles on their record players, they'd be the entire Hot 100 every week from 1964-1970.