Virtually and practically are synonyms - meaning all but, nearly. Practically usually refers to practical purposes, however its meaning has been extended to mean 'nearly, all but'.
Language critics sometimes object when the notion of practicality is stripped from the word 'practically'.
This paper has virtually no mistakes. (practically - sounds wrong here).
The car was practically undrivable. (virtually - sounds less right to me).
Source:
https://www.usingenglish.com/forum/threads/43198-virtually-and-practically
