Computer science applications are a combination of hardware and software. High performance can only be achieved if both components are well coordinated. Information is represented in binary form and processed electronically. The computer systems used today still largely follow the architecture of the "Von Neumann computer". Modern developments, however, show a structural change, triggered by the new possibilities in the realisation of hardware and software. Various directions of development can be discerned:

The computer systems are increasingly becoming an integral part of the applications themselves. One then speaks of an "embedded system", a system in which the computer system as such remains hidden from the user. Every mobile phone, for example, has a computer system as its functional core, with which the information "speech" is processed and at the same time all the functions required for communication are handled. Even the process of sending and receiving via the high-frequency part of the mobile phone is carried out digitally (keyword: "software defined radio").

The approach to hardware development has changed fundamentally. Today, the development process of an electronic circuit corresponds more to a programming task (via hardware description languages such as VHDL or Verilog) and less to an engineering process. The computer as a development tool is indispensable in this process. This opens up a multitude of new possibilities.

New techniques are being used in an attempt to overcome the various disadvantages of the computer systems used up to now. The common concept of "hardware first", in which the computer system is rigidly predefined to a large extent and the various functions are realised by software, is increasingly being abandoned. Modern concepts envisage a hardware platform that is variable within wide limits and can be optimally adjusted to the requirements of the individual applications (keyword: "(re)configurable logic"). In the future, applications will therefore rather be developed as a holistic system (hardware and software) in order to achieve the highest performance with the smallest possible dimensions and lowest energy consumption (keyword: "hardware/software codesign"; however, still difficult to realise). Programming languages such as SystemC are already known for hardware/software codesign. This means that hardware aspects are once again coming more to the fore in computer science.

Many functions that are realised today via software will be realised to a greater extent via hardware in the future. This makes it much easier to handle concurrent processes, for example. This is made possible by the improved possibilities to develop powerful hardware components. As an example, one can cite the developments in the area of "Java in Silicon". The aim of this development is to realise the virtual machine for Java not as software but as hardware. There are already pure Java processors that use Java as a "machine language".

In the realisation of hardware, the development of a system on a chip (system-on-chip) plays an increasingly important role today.

Modern applications are realised as distributed - in part highly distributed - systems. In addition to many advantages for the realisation of applications, a characteristic feature of such systems is communication. A wide range of wired and wireless technologies are used. The wired technologies are increasingly dominated by Ethernet technology. With regard to the protocols used for communication, there is an increasing trend towards TCP/IP-based communication in all areas. Different technologies are used for wireless communication, depending on whether communication is carried out over short distances (e.g. with Bluetooth or Zigbee), over medium distances (e.g. WLAN) or over long distances (e.g. UMTS).