What Is The Function Of Plasma In Blood?

Plasma is actually the medium in which all the chemical reactions vital for our body takes place along with the certain cell activities
Plasma mainly consist of WBC ( white blood cells) which helps in healing the wounds, in spite of that they are anti bacterial and helps the body to resist certain viruses and bacterias. Blood is a soft connective tissue  and so is composed by complex structures

Plasma is the fluid matrix in which red blood cells and white blood cells are suspended into. Plasma is made of inorganic salts, proteins (immunoglobulins, albumins, fibrinogens), nutrients, metabolic waste products, and respiratory gases. Plasmas main functions are to act as buffers, maintain osmotic balance and to contribute to viscosity of blood.

Wow! That's a big question.
Plasma contains, among other things, the clotting agents.  When you get a wound, these agents aid in healing and stopping the bleeding.

Plasma also contains proteins that help carry insoluble materials to/from cells as needed.

Plasma also contains antibodies (gammaglobulins) to help resist/fight off infections.

This is really just the tip of the iceberg though.  There are whole chapters and books written on the role of plasma!

Plasma is basically just the liquid part of the blood. Its what all the blood cells and other components of the blood are suspended in, and where all the chemical reactions take place. The blood plasma is what really acts as the transport system of the body, allowing oxygen and nutrients from food to be transported to all the cells of the body. Without the blood plasma the blood wouldn't be blood really, it would just be loads of different cells.

It carries blood away from the heart .Viens returns blood to the heart.

Plasma does not contain white blood cell or platelet (clotting). They are called the formed elements. Blood is made up of formed elements and plasma. Plasma contains mostly water (91.5 %) and solutes (proteins).