Temporary Residence Permit in the Russian Federation

Any foreign citizen entering Russia under a visa or a visa-free regime, having a migration card and no residence permit or no permit for temporary residence in Russia, has a "Temporary Visitor Status".
The period of stay of a foreign citizen cannot exceed 90 days from the date of entry into the Russian Federation, except for the cases when a foreigner visits Russia for work purpose and obtains a proper Work Permit.

For those foreign citizens willing to stay in Russia for a longer period or intending to obtain Residence Permit or Russian Citizenship, it is necessary to acquire "Temporary Resident Status" in the first place.
TEMPORARY RESIDENCE PERMIT (TRP) is a document granting a foreign citizen the right for temporary residence in the Russian Federation before obtaining Residence Permit or Russian Citizenship.
Temporary Residence Permit is valid for 3 years, so is the registration at the place of residence. This saves the trouble of undertaking migration registration procedure (registration of notifying character) each time a foreigner enters the Russian Federation.

Source: http://residencepermit.blogspot.com/