Here are some of the commonly known tourist visa types for Singapore:

1. Singapore Tourist Visa (also known as Singapore Visitor Visa): This is the standard tourist visa that allows visitors to enter Singapore for tourism purposes. It is typically valid for a short duration, such as 30 or 90 days, and may have single or multiple entry options.
2. Singapore Electronic Arrival Card (SG Arrival Card): Instead of a traditional visa, citizens of select countries may be eligible to apply for an electronic arrival card online. The SG Arrival Card is valid for a single entry and allows for a stay of up to 14 or 30 days, depending on the nationality.
3. Singapore Transit Visa: If you are transiting through Singapore and will be in the country for a short period, you may need a transit visa. The specific requirements and eligibility for a transit visa depend on your nationality and the length of your layover.
4. Singapore Business Visa: While not strictly a tourist visa, the Singapore Business Visa allows individuals to visit Singapore for business-related activities, such as attending conferences, meetings, or exploring potential business opportunities. This visa category is distinct from tourist visas and requires specific documentation related to the purpose of the visit.