Some material is transported by the gradient of the molecule which was called osmosis. Material using this method is oxygen, water. Glucose can transported passively by GLUT4. Cholesterol is hydrophobic and can enter cells easily by diffusion.
Big molecule might need to be digested by enzyme before transported.
Active transport need energy (ATPs) to be used. This method is used NA+K+(sodium-potassium) ATPase pump.