Short term visa is an individual single-entry, double-entry or multiple-entry visa enabling a foreigner to enter the Republic of Latvia within the specified period of time, once, two times or an unlimited number of times and accordingly stay there for the term indicated in the visa and depart from the country.
The maximum length of stay in the Republic of Latvia with a short-term visa may not exceed 90 days within a six-month period.
The maximum term of validity of a short-term visa is one year. A multiple entry short-stay visa may be issued with a period of validity up to two years for a foreigner who during two previous years has received a residence permit in Latvia or at least a multiple entry short-stay visa and has used it in accordance with the legislation and who has ground for receipt a multiple entry visa.
More information: http://www.udgm.gov.lv/en