Visas vary from country to country when it comes to their designs. But they usually all carry the same information. Each information that is on the visa needs to correspond with the information stated in the passport.
Visas are as a rule written in the language of the issuing country with explanations in English.
Here is what the tourist Vietnamese visa looks like and what information can be found on it.
(1) Vietnamese coat of arms;
(2) Full name of the country in Vietnamese and English;
(3) Where the visa was issued at (this one was issued in Bern, Switzerland);
(4) When was the visa issued;
(5) The official stamp of the Vietnamese embassy/consulate and signature of an administrative officer;
(6) Visa identification number;
(7) Category/Type of the visa (for example, this one is DL, which is a tourist visa);
(8) From which date is the visa valid;
(9) Date when the visa expires;
(10) Number of entries (for Vietnam there are only single or multiple entry visas, this one is a single entry visa);
(11) Passport number;
(12) and (13) are for additional information about the visa and the duration of stay.
Once you get your processed visa always double check all the information on it.