Validator nodes are an upcoming functionality of Electra Protocol and they are listed in the 2022 roadmap. Using a validator node, the network will be able to confirm transactions faster than right now (full confirmations within a second).
Anyone interested to run a validator node will be able to do so, when the technical and financial requirements by the operator are met. The precise requirements are not yet public. However, it is expected that future validator node operators have to hold millions of XEP in order to become a node operator. As a compensation, it is also expected that validator node operators on the Electra Protocol blockchain get a higher reward than users performing XEP staking.
The purpose of the upcoming validator nodes of Electra Protocol is entirely to speed up validation process.