What is the primary function of rectification in electrical systems?

The primary function of rectification in electrical systems is to convert alternating current (AC) into direct current (DC). This is achieved through the use of diodes, which allow current to flow in only one direction. AC is characterized by its alternating voltage and current that changes direction periodically, while DC has a constant voltage and current flowing in one direction.

Rectification is essential in many applications, such as in power supplies for electronic devices, where DC is required for the functionality of circuits and components. In the process of rectification, the AC waveform is transformed, effectively producing a DC output, which can then be smoothed and regulated for use.

The other options relate to different functions within electrical systems. Increasing voltage levels pertains to devices like transformers, which primarily adjust voltage but do not convert AC to DC. Decreasing current flow sometimes applies in circuit design or through resistive elements, but this does not describe the specific role of rectification. Filtering high frequencies is associated with signal processing techniques, often involving capacitors or inductors, to remove unwanted frequency components, distinct from the primary action of converting AC to DC.