Definition - What does Filter mean?
A filter is a device used to remove impurities from a substance. There are mechanical filters, electrical filters and digital filters may take the form of anti-virus software. Filters allow equipment to run effectively and preventing impurities that may cause malfunctioning and, consequentially, safety issues.
Safeopedia explains Filter
For the safe operation of equipment on a work site, it is imperative that a regular program of filter maintenance be adhered to. Filters that are used in machinery have cartridges in them. These cartridges have a limited life span. Unless cartridges are regularly cleaned or replaced, they will not provide an adequate level of filtering protection. Examples of mechanical filters can include those used to filter oil or fuel. Electrical filters can include those used to filter out unwanted signals, while digital filters can include anti-virus software.