Operations are simply the amount of available and used processing power for various Projects. It is expressed as CURRENT VALUE / MAXIMUM VALUE, for example 14,422 / 18,000.
The maximum amount of Operations you can have stored is based on the amount of Memory (Computational Resources) you've purchased.
It is increased by having Processors (Computational Resources); the more Processors you have the faster it increases.
It can also be increased or decreased by using the "Compute" function of Quantum Computing