You don't need a giant mixing console and soundboard to record music in your home studio. A quality laptop with recording software on it can handle functions which used to require professional producers and a roomful of equipment. Using a program like Pro Tools, Cubase or Sonar, you can take raw sound into your computer and turn it into something cohesive and marketable. Your laptop will convert this sound into numbers that you can manipulate and mix down, in a process known as digital recording,
In order to convert music into numbers on a laptop, you'll need to collect it first, and this is where a microphone comes in. Any type of microphone, whether it be a condenser or a dynamic, will work. A microphone picks up sound and converts it into an electrical signal,. You can manipulate this signal on your laptop, making it louder, increasing reverb, etc. You can use a microphone to pick up vocals and sound coming out of amplifiers, like those produced by a guitar or keyboard.
While it's possible to plug a microphone directly into a laptop and start recording, it's preferable to incorporate an audio interface to handle the sound coming in and out of your computer. An audio interface, like those made by M-Audio or PreSonus, is a professional-grade soundcard which allows for real-time recording. This cuts back on latency and delivering high-quality sound. Using an audio interface will help you achieve a fidelity to the original sound usually reserved for producers at professional studios.
A laptop may be able to turn raw sound into the next big pop hit, but one thing it can't usually handle on its own is monitoring. Most laptop speakers are small and deliver only decent-quality sound. In order to fully realize the quality of your music, you'll need a pair of high-quality speakers connected to your laptop. Connecting monitors to your laptop will make it possible for you to hear issues in your recordings and make adjustments accordingly.