What is meaning of chal's law

Charles's law (also known as the law of volumes) is an experimental gas law that describes how gases tend to expand when heated. A modern statement of Charles's law is: When the pressure on a sample of a dry gas is held constant, the Kelvin temperature and the volume will be in direct proportion.[1] This relationship of direct proportion can be written as: {\displaystyle V\propto T}{\displaystyle V\propto T} So this means: {\displaystyle {\frac {V}{T}}=k,\quad or\quad V=kT}{\displaystyle {\frac {V}{T}}=k,\quad or\quad V=kT} where: V is the volume of the gas, T is the temperature of the gas (measured in kelvins), and k is a non-zero constant. This law describes how a gas expands as the temperature increases; conversely, a decrease in temperature will lead to a decrease in volume. For comparing the same substance under two different sets of conditions, the law can be written as: {\displaystyle {\frac {V_{1}}{T_{1}}}={\frac {V_{2}}{T_{2}}}\qquad {\text{or}}\qquad {\frac {V_{2}}{V_{1}}}={\frac {T_{2}}{T_{1}}}\qquad {\text{or}}\qquad V_{1}T_{2}=V_{2}T_{1}.}{\displaystyle {\frac {V_{1}}{T_{1}}}={\frac {V_{2}}{T_{2}}}\qquad {\text{or}}\qquad {\frac {V_{2}}{V_{1}}}={\frac {T_{2}}{T_{1}}}\qquad {\text{or}}\qquad V_{1}T_{2}=V_{2}T_{1}.} The equation shows that, as absolute temperature increases, the volume of the gas also increases in proportion.