The integration of DGs with utility grids via the micro gridconcept presents numerous obstacles. Power islanding is a severe technical issue associated with the interconnection of DGs.An island is a scenario in which DG disconnects from the grid and satisfieslocal electric loads autonomously. This causes security and voltage stabilitychallenges for the service, as well as a failure to maintain voltage and frequencywithin appropriate operational parameters. As a result, detecting instances of islandingand protecting the DG become critical issues. Islanding is classified into two types:purposeful and inadvertent. During purposeful islanding, DG unit acts as abackup to a network failure in order to boost reliability similar to a UPS. However,unintended islanding happens when a portion of the load is sent through a DG or setof DGs when the network is down.This paper presents the overview of various active, passive, hybrid, intelligent and signal processing islanding detection techniques used for speedy detection of islanding