Isothermal amplification and PCR (polymerase chain reaction) are two types of nucleic amplification techniques. There are a few key differences between these two techniques. 

Isothermal amplification 

Isothermal amplification is a technique that copies nucleic acids without temperature cycles. It is carried out at constant temperature using amplification machinery. Unlike PCR, isothermal amplification does not require a thermal cycler. Instead, it exponentially amplifies target sequences using special strand-displacing DNA and specially designed primer sets. This helps it to overcome limitations inherent in PCR. 

PCR

PCR requires temperature changing cycles for amplification. A thermal cycler with rapid heating and cooling mechanisms is a mandatory requirement for the process. During PCR, DNA polymerase extends primers on a single strand of DNA.