When traveling to Europe and entering the Schengen Area from a country without visa-free access, you must apply for a Schengen visa, which falls into four main categories: A, B, C, and D. The Uniform Schengen Visa is the most common type, encompassing categories A, B, and C. It grants you an airport transit visa and permits stays of up to 90 days within a six-month period in any Schengen Zone country. This visa is suitable for short vacations in Europe.

1. The Type A Schengen visa, also known as the Airport Transit Visa, permits citizens of non-Schengen states to transit through or wait for connecting flights within the international zone of a Schengen country's airport. It is mandatory for travelers moving from a non-Schengen to another non-Schengen country with connecting flights in a Schengen country's airport. Holders of a Type A visa are prohibited from entering the Schengen country.

2. The Type B Schengen visa, intended for journeys lasting fewer than five days, has been replaced by the Type C visa, with the stipulation of "transit."

3. The Type C Schengen visa, also known as the short-stay Schengen visa, is the most common type issued by Schengen area countries' visa services, including embassies, consulates, and appointed external providers. It permits the holder to stay or travel freely within the Schengen area for less than 90 days within a 180-day period.

For citizens of certain countries, obtaining a Category C Schengen visa is obligatory. To determine if you need one, review the Schengen visa entry requirements.

Depending on the purpose of your trip, the Type C Schengen visa can be:

• Single-entry visa : Allows one entry into the Schengen area. Exiting the area renders the visa invalid, even if its validity period has not expired.
• Double-entry visa : Permits two entries into the Schengen area during the visa's validity period. This allows for exiting and re-entering the area within that timeframe. After the second exit, the visa expires.
• Multiple-entry visa : Grants the holder permission to enter and exit the Schengen area multiple times. This authorization is valid for a maximum of 90 days within a 180-day period.

4. The Type D Schengen visa, also known as the national long-stay visa, is required for individuals planning to study, work, or reside in a Schengen country for more than 90 days (up to 1 year). This visa permits travel and stay within the Schengen area outside of the initially selected Schengen country for up to 90 days within a 180-day period and throughout the visa's validity period.

Travel purposes that justify applying for a Category D visa include:

• Tourism or private visits
• Professional activities
• Study, participation in a training program, or completion of an internship
• Family reasons

The national visa or Type D visa is issued by the consular authorities of the intended Schengen country in compliance with national legislation. Therefore, contacting the country's services is necessary to understand the various conditions and formalities required. Under certain circumstances, it can be issued as either a single or multiple-entry long-stay visa.

The types of multiple-entry visas include:

1. One-year multiple-entry Schengen Visa:

   - To apply for this visa type, you must have utilized three visas within the preceding two years.

   - Proof of previous visas and trips to the Schengen Area is required during the application process.

   - Allows entry for up to 90 days within each 180-day period.

2. Three-year multiple-entry Schengen Visa:

   - Granted to applicants who have previously obtained and lawfully used a multiple-entry visa valid for one year within the last two years.

   - The 90/180 rule applies.

3. Five-year multiple-entry Schengen Visa:

   - Available to applicants who have obtained and lawfully used a multiple-entry visa valid for at least two years in the past three years.

90/180 Schengen Visa Rule:

It's crucial for multiple-entry visa holders to understand the 90/180 rule. While many assume the 180-day period begins when their visa is issued, it's a rolling timeframe. This means you must calculate backward from your intended re-entry date into the Schengen Area to ensure you haven't spent more than 90 days there within the past 180 days.

Limited Territorial Visa

A Limited Territorial Visa is another type of visa that restricts travel to just one country. These visas are typically issued in special or emergency circumstances when obtaining a standard visa to visit Europe is not possible.