Like the ones you plug your cheap headphones into. So, you had to use adapters to connect the inputs and outputs to your other equipment. The card-mounted jacks have contacts that become loose and noisy. Drive with RCA connectors for analog output as well as input. These are digitized samples of any sound you can think of-instruments, sound effects, human voices, synth sounds, etc.
Commercial packages abound, often starring major performers as the source of the samples.
But there are many fine Soundfonts available for free on the Net. Shared Memory and Processing. This means your MIDI sequenced music can sound amazingly real. This design takes advantage of the more powerful processor you have in your PC, and obviously, saves on the cost of the card. The heart of the SBLP is the EMU10K1 audio processor.