In a homogenous mixture, sugar was the solute and water was the solvent. Solubility is the maximum amount of a solute that dissolves in a given amount of solvent at a constant temperature. Solutes are more soluble in a given solvent at higher temperatures. Therefore, when temperature increases, the solubility of the solute also increases.
Moreover, the solubility of the substance ranges from infinitely soluble such as alcohol in water, to poorly soluble like silver chloride in water and the species that dissolves, the solute, can be another liquid, gas or a solid.