Bernoulli's equation is an indispensable tool for the analysis of flow of liquids. 

Bernoulli's equation states that for two points $1$ and $2$ lying on a streamlined flow, they can be related in terms of the pressure difference between them, their relative height and velocities of the fluid at those points. The formula is given below:

$P_1-P_2=\frac{1}{2}\rho ({v_2}^2-{v_1}^2)+\rho g(h_2-h_1)$

where,

$P_1-P_2$ is the pressure difference between points $1$ and $2$,

$v_1$ is the velocity of the fluid at point $1$,

$v_2$ is the velocity of the fluid at point $2$ and

$h_2-h_1$ is the height difference between them.