The primary characteristic of a polar molecule is its asymmetrical distribution of electrical charge. This feature occurs when there is a significant difference in electronegativity between atoms covalently bonded together, resulting in partial positive and negative charges within the molecule. Water is a prime example, with its oxygen atom carrying a partial negative charge and hydrogen atoms carrying partial positive charges. This polarity leads to unique properties, such as the ability to dissolve many substances and engage in hydrogen bonding, influencing chemical and biological processes.