PPMs

PPMs is an acronym that can refer to several concepts across different fields. The exact meaning depends on the context, with common usages in science, business, engineering, and computing.

Parts per million (ppm) is a unit of concentration representing one unit of substance per one million units of mixture. It is used for gases, liquids, and solids, and can be expressed by mass (ppm by mass) or by volume (ppm by volume). In water chemistry, 1 mg/L is roughly equivalent to 1 ppm.

Project portfolio management (PPM) is a discipline within project management that focuses on selecting, prioritizing, and governing a company’s projects to maximize strategic value and resource efficiency. Practices include defining criteria for project approval, balancing the portfolio, tracking benefits, and coordinating interdependencies among initiatives.

Pulse-position modulation (PPM) is a digital modulation scheme in which information is conveyed by the timing of a pulsed signal within a fixed time frame. It is used in some optical and wireless systems, especially where power efficiency or simple receivers are important.

Portable pixmap (PPM) is one of the Netpbm image formats. It encodes color images in a simple text (P3) or binary (P6) format, with a header specifying width, height, and maximum color value. The format is widely used for teaching and basic image processing tasks.