Stellar multiplicity is a common outcome of the star formation process. Understanding the frequency and characteristics of multiple systems, and their dependence on primary mass and environment, is crucial for studying this process. Recent advancements in instrumentation have enabled robust analyses of stellar multiplicity, particularly for main sequence (MS) stars and brown dwarfs, as well as pre-main sequence (PMS) and embedded protostars. Trends in multiplicity as a function of mass and evolutionary stage provide a basis for comparing with numerical and analytical models of star formation. The multiplicity of solar-type stars (0.7-1.3 M☉) is around 62% for companions and 44% for multiple systems. The orbital period distribution is log-normal, with a peak around 250 years. The mass ratio distribution is flat, with a slight peak at higher mass ratios. High-order multiple systems are common, with about 25% of all solar-type systems being triples or higher. The mass ratio distribution for solar-type binaries is flat, with a peak around q ≈ 1 for short-period systems and q ≈ 0.3 for long-period systems. Low-mass stars (0.1-0.5 M☉) have a multiplicity frequency of around 26% for companions and 33% for multiple systems. The orbital period distribution is log-normal, with a peak around 5.3 AU. The mass ratio distribution is flat, with a slight peak at higher mass ratios. High-order multiple systems are also common, with about 21% of all low-mass systems being triples or higher. VLM stars and substellar objects have a multiplicity frequency of around 20-25% for companions. The orbital period distribution is narrow, with a peak around 4-7 AU. The mass ratio distribution is skewed toward equal mass systems. High-order multiple systems are less common, with about 21% of all VLM systems being triples or higher. Intermediate-mass stars (1.5-5 M☉) have a multiplicity frequency of around 50% for companions and 100% for multiple systems. The orbital period distribution is bimodal, with peaks around 10 days for SBs and 350 AU for VBs. The mass ratio distribution is flat, with a peak around q ≈ 0.4. High-mass stars (M☉ ≥ 8) have a multiplicity frequency of around 70% for companions and 100% for multiple systems. The orbital period distribution is log-normal, with a peak around 3000 days. The mass ratio distribution is flat, with a peak around q ≈ 0.8. Old stars (Population II) have a multiplicity frequency of around 39% for companions and 26% for multiple systems. The orbital period distributionStellar multiplicity is a common outcome of the star formation process. Understanding the frequency and characteristics of multiple systems, and their dependence on primary mass and environment, is crucial for studying this process. Recent advancements in instrumentation have enabled robust analyses of stellar multiplicity, particularly for main sequence (MS) stars and brown dwarfs, as well as pre-main sequence (PMS) and embedded protostars. Trends in multiplicity as a function of mass and evolutionary stage provide a basis for comparing with numerical and analytical models of star formation. The multiplicity of solar-type stars (0.7-1.3 M☉) is around 62% for companions and 44% for multiple systems. The orbital period distribution is log-normal, with a peak around 250 years. The mass ratio distribution is flat, with a slight peak at higher mass ratios. High-order multiple systems are common, with about 25% of all solar-type systems being triples or higher. The mass ratio distribution for solar-type binaries is flat, with a peak around q ≈ 1 for short-period systems and q ≈ 0.3 for long-period systems. Low-mass stars (0.1-0.5 M☉) have a multiplicity frequency of around 26% for companions and 33% for multiple systems. The orbital period distribution is log-normal, with a peak around 5.3 AU. The mass ratio distribution is flat, with a slight peak at higher mass ratios. High-order multiple systems are also common, with about 21% of all low-mass systems being triples or higher. VLM stars and substellar objects have a multiplicity frequency of around 20-25% for companions. The orbital period distribution is narrow, with a peak around 4-7 AU. The mass ratio distribution is skewed toward equal mass systems. High-order multiple systems are less common, with about 21% of all VLM systems being triples or higher. Intermediate-mass stars (1.5-5 M☉) have a multiplicity frequency of around 50% for companions and 100% for multiple systems. The orbital period distribution is bimodal, with peaks around 10 days for SBs and 350 AU for VBs. The mass ratio distribution is flat, with a peak around q ≈ 0.4. High-mass stars (M☉ ≥ 8) have a multiplicity frequency of around 70% for companions and 100% for multiple systems. The orbital period distribution is log-normal, with a peak around 3000 days. The mass ratio distribution is flat, with a peak around q ≈ 0.8. Old stars (Population II) have a multiplicity frequency of around 39% for companions and 26% for multiple systems. The orbital period distribution