Generally you have to use the default pc, laptop mic to capture sounds and audio but it requires an recording application for it. A quick and easy way is to record sound online. Here are two very useful tools to record music, audio or voice messages online free with a click of a mouse button.
Vocaroo.com (link) Free Online Voice Message Recorder
Vocaroo is a simple free online tool to record sound online for sending voice messages across the web. The audio is captured from you default audio input device from your PC or the microphone of your laptop.
Go to Vocaroo and Click "Click to Record" to start recording online. Once done you can send the recorded message to an email or use the embed code to add it your blog posts as podcasts, audio instruction on a webstite etc.
Soundation Studio (link) Advanced Music Recorder and Sound Editor Online
Whether you are an amateur or a pro you will be able to satisfy all your needs with Soundation Studio, a powerful online sequencer with 11 real time effects, 3 synthesizers, a drum machine and a fully integrated Sound Shop.
The program recently allows adding music, sounds through the web application and mix with your web editor, now we can also record directly from the microphone by adding the corresponding track. Virtual instruments, effects, synths, sounds free license and ability to send and save files from your computer … a good editor to take this into account.