Blood is a special connective tissue consisting of a fluid matrix called plasma and formed elements like RBCs, WBCs, and platelets. Plasma is straw-coloured and viscous, containing proteins such as fibrinogen, globulins, and albumins.

Lymph is a colourless fluid present in the lymphatic system. It is derived from blood as interstitial fluid that moves out of capillaries into tissue spaces. Lymph contains specialised lymphocytes responsible for immune responses.

The main differences are: (i) Blood has straw-coloured plasma while lymph is colourless, (ii) Blood contains all formed elements (RBCs, WBCs, platelets) while lymph mainly has lymphocytes, and (iii) Lymph has lower protein content compared to blood as larger proteins remain in blood vessels. Lymph also carries nutrients, hormones, and absorbed fats from lacteals.