So, let's look at an example of equilibrium in the cookie market and see what happens when things change. Let's say the equilibrium price for a chocolate chip cookie is $3. Here's an example of the supply and demand curves, with an equilibrium price of $3, which is at the intersection of the supply and demand curves.
A sigma bond is the end-to-end overlap of the bonding orbitals, usually hybrid orbitals. The sigma bond is a single bond. A pi bond is the side-to-side overlap of unhybridized p-orbitals. A pi bond, along with a sigma bond form a double bond. A triple bond is two pi bonds and a sigma bond. Take a look at this diagram showing a sigma bond and a pi bond, forming a single bond and a double bond. http://metafysica.nl/ethylene01.jpg.
A typical double bond consists of one sigma bond and one pi bond; for example, the C=C double bond in ethylene. A typical triple bond, for example in acetylene, consists of one sigma bond and two pi bonds in two mutually perpendicular planes containing the bond axis. Two pi bonds are the maximum that can exist between a given pair of atoms. Quadruple bonds are extremely rare and can be formed only between transition metal atoms, and consist of one sigma bond, two pi bonds and one delta bond.