Tier - A tier is a multi-layer cake, beginning with the smallest cake on top and the largest on bottom. For example, the cake photographed above is a 3 tier cake.
Layer - A layer is a single sheet of cake. Most cakes multiple layers in each tier. This gives each tier their height.
Filling - Usually made from fruit or creams, fillings go inbetween each layer. Not only do they act as a gel to hold each layer together, they are a tasty addition to your cake. If you aren't a filling person, icing is always a good alternative.
Stacked - A stacked cake is a cake where each tier is placed directly on top of the tier underneath it.
Pillar - A pillared cake has 4 pillars supporting a plate. Each layer is placed upon the plate and the pillars go into each tier. This gives the cake a little extra height.
Sculpted - A sculpted cake is a traditional shaped cake that is cut and molded to create a certain shape. For example, a cake made to look like a football is a sculpted cake.
Border - A border is the piping at the bottom of each tier. This is what hides the board underneath it and there are various different styles and designs for borders.
Scroll - The scroll is the design, also called piping, on the side of the cake. This is what decorates and customizes the cake.
If you ever are unsure about a term your baker is using, feel free to ask! We love to answer questions and I for one, want to make sure that every couple and I are on the same page when it comes to their wedding cake!