Follow the instructions on the pasta package to cook the fettuccine noodles al dente.
While the pasta is cooking, finely grate the parmesan cheese. I recommend starting with a block of parmesan cheese rather than the pre-packaged shredded parmesan. However, if you only have pre-shredded cheese, I would run it through a food processor before adding to the sauce to make sure it's finely shredded and will melt easier. I strongly discourage you from using the powdered cheese in a shaker as it won't melt into the sauce very well.
To make the Alfredo, start by melting the butter on medium heat in a skillet. You can cut the butter into pieces to speed up the process.
Once the butter is melted, add the minced garlic and cook until the garlic is fragrant (around a minute or two).
After the garlic is cooked, add the heavy whipping cream and bring to a simmer, stirring frequently to make sure your cream doesn't burn.
Once the mixture comes to a boil, reduce the heat to medium low and simmer for 5 minutes, stirring frequently.
After the sauce is done simmering, slowly add the grated parmesan cheese, stirring constantly until the cheese is melted and incorporated into the sauce.
Gently mix the cooked fettuccine into the sauce until all the noodles are evenly coated.
Garnish with fresh chopped parsley, serve, and enjoy!