Fonts are classified by whether or not they have "serifs," or those little lines capping the ends of each letter. Serifs lean toward a traditional and formal look. "Slab serif" is another variation of this, with serifs that are flat or squared off. "Sans-serif" typefaces have no serifs and appear more modern. Script fonts are designed in a fluid, cursive style and can range from casual to formal in appearance.
Fonts in each of these categories can be combined together in the same invitation. For example, it's common for names to be in a script font and all remaining text in a serif font so the details are easier to read. There's no hard-fast rule to pairing fonts that look great together, but it tends to work better with two (three at the very max) that have contrasting styles yet complementary personalities.
When it comes time to pick your fonts, you may wonder why some are free for download while others come with a price tag. Just like there are professional graphic designers, makeup artists and pastry chefs, there are professional typographers who design fonts. These folks have an in-depth knowledge of how letterforms work together and take their time tediously designing each little stroke, swash and serif. On the other hand, free fonts can be created by anyone with a computer; so while there are some truly great free options out there, there are even more that look amateur or overused. Free fonts can be fun for certain events (theme parties, holidays, etc.), but for weddings and high-end events, you may want to invest in a professionally designed font that will look top-notch. Choose wisely! We've listed some great links at the end of the article for font download resources.
With that said, here are some fonts (both pro and free) to act as a starting point for inspiration. If all this font business is overwhelming, enlist the help of a graphic designer. They work with type for a living and can help narrow down some options based on the style of your wedding. For a more custom look, work with a calligrapher or hand-lettering artist to create one-of-a-kind typography on your invitation.