Students from EU/EEA countries and Switzerland are exempt from student visa requirements. To enter Czechia, EU students only need a valid passport or national ID card. Holders of a long-term residence permit or a long-term visa for the study purpose issued by a different EU member state may also remain in Czechia without needing a visa, but only up to 1 year. This visa-free stay only applies to participants of exchange programs (e.g. Erasmus) and their permit/visa has to bear a note "student" and the name of the exchange program.
Students from countries outside the EU are required to obtain a visa or a residence permit. Czech visa is issued by the Czech embassy or consulate in your home country where you can also get more information. Please note that the whole procedure can take up to 60 days, so it is recommended to apply for the visa well in advance. Check the website of the Ministry of Interior of the Czech Republic for the latest information on visa/permit requirements.