The goal of this research is an effective connection of geographically distant computing and storage servers. Eligible users can access these resources from different institutions anywhere in the world. Access points for computing (Computing Elements) and data (Storage Elements) are defined together with Workload Management servers for computing jobs distribution. Several other serveces for monitoring and accounting are operated. Usually there are several competing implementations of such services; they can interoperate thank to well defined interfaces. After several years of development the scalability of grid solutions increased to current many hundreds of thousands of computing cores used simultaneously and worldwide data transfers of tens of gigabits pers seconds. Grid can connect different computing resources like dedicated clusters, private and public clouds and supercomputers in HPC centers. Different operating systems are supported via container solutions like docker and singularity.
