what is the multimedia and the tools

The word "Multimedia" simply means being able to communicate in more than one way. This means that, whether you are aware of it or not, you already give multimedia presentations. For example if you rub your temples while telling someone you have a headache or when you point to a diagram on a board whilst speaking to a class of students you are using multimedia to get your point across. In this instance you are using movement in conjunction with sound and image.
So multimedia is all about communicating in several ways.
about the multimedia tools as we know macromedia flash and Macromedia Director both are the proven multimedia authoring tools for professionals. macromedia flash is the most advanced authoring environment for creating rich interactive content including websites, online advertisements, instructional media, presentations, games, and mobile device content.

Macromedia Director combines broad media support for media types, ease of use, high-performance, and an infinitely extendible development environment to deliver rich content and applications for CDs, DVDs, kiosks, and the Internet. Director MX 2004 offers powerful new features, including two scripting languages, DVD-Video support, cross-platform publishing, and Flash MX 2004 integration.

Macromedia Flash and Director are both powerful rich-media content solutions. Used together, they enable developers to create the most compelling and effective rich content, both on- and offline. Many Director users have already discovered the advantages of combining Macromedia Flash with Director, while more Macromedia Flash users than ever are also discovering this powerful combination.

Use Macromedia Flash to create streaming vector animation, lightweight video, and Rich Internet Applications, both for devices and the web.
Use Director MX 2004 to create extensible multimedia content that utilizes long form (or streaming) video, including advanced 3D games and learning applications, deployable across multiple mediums.
Then combine the two solutions to build the most engaging, powerful, and easy-to-deploy Internet content that leverages the strengths of both applications.