What is most true about glaciers?

Glaciers are massive, slow-moving bodies of ice formed from compacted snow that accumulate over time in cold regions. They play a crucial role in the Earth's climate system, acting as fresh water reservoirs and influencing sea levels. As global temperatures rise, many glaciers are retreating, leading to significant ecological and hydrological changes. Their melting contributes to rising sea levels, which poses risks to coastal communities worldwide.