Theory:

In plants, diffusion and active transport are used to transfer materials into and out of the cells.
 
shutterstock1760655569 (1).jpg
Active transport and passive transport
Active transport:
The type of transport which utilizes energy to pump molecules against a concentration gradient is known as active transport.
Active_Transport_-_Protein_Pumps.png
Active transport: Pumps
 
This transport is carried out by membrane bound proteins which use energy to transport the substances across the cell membrane and are often referred to as pumps. These pumps transport the substances from a low concentration to a high concentration and is hence known as uphill transport.
Passive transport:
The type of transport which does not utilize energy to pump molecules along the concentration gradient is known as passive transport.
Types of passive transport:
  • Osmosis
  • Diffusion
  • Facilitated diffusion
 The movement of ions and molecules along the concentration gradient without the application of any external energy.
Diffusion:
shutterstock388835710.jpg
Before and after diffusion
Diffusion is described as the free movement of solid, liquid and gaseous molecules from a higher concentration to a lower concentration without the usage of energy is known as diffusion.
As it occurs without the involvement of energy it is a passive process.
 
The process of diffusion
Reference:
https://upload.wikimedia.org/wikipedia/commons/4/45/Active_Transport_-_Protein_Pumps.png