In simple terms, according to dictionaries "ALUNO" is anyone who receives training or instruction and "ESTUDANTE" is who studies. To understand the difference, I think aditional translations for "ALUNO" would be "PUPIL" or "DISCIPLE" and an aditional translation for "ESTUDANTE" would be "LEARNER". In practice, there are many situations where these words are used as synonyms. For example if you talk about who attends any education establishment you can use "ESTUDANTE" or "ALUNO". Only in situations where there is no teacher, you need to use "ESTUDANTE", for example, a person that learn a language by himself.

https://www.youtube.com/watch?v=yaa6oUwKvec To be an "aluno" you just need to step inside a classroom—and it doesn't matter whether you pay attention or not. To be an "estudante" you must study—and it doesn't matter whether you're in a classroom or not.

ALUNO (the Latin alumnus, alumnié) is the individual who receives training and instruction of one or more teachers or teachers to acquire or expand their knowledge, usually in intellectual areas, taking into account that there are different skills and styles learning for every student - especially as they advance in school life. Sometimes uses the term as a synonym for ESTUDANTE, a person who takes care of the study, concerning a level of any learning. However, the study can be an individual activity without recourse to teachers. A distinction is made, therefore, between ALUNO and ESTUDANTE. The ESTUDANTE word (the verb estudar) refers to the individual who engages in some sort of study that seeks the intellectual food on their own, can do this individually or without the use of teachers. Here in Brazil, we use both, without difference, because they are much similar. "Os estudantes da faculdade de Arquitetura" é o mesmo que "Os alunos da faculdade de Arquitetura". Or "Eu sou estudante de Arquitetura", que soa melhor que "Eu sou aluna de Arquitetura". You use more ESTUDANTE when you wanna say you are student of some area or something especific. And you should use ALUNO when you need tell you are student of that Teacher or that class. Ambas estão corretas, você precisa apenas ficar atenta à concordância nominal da frase.

Hi! Yes, both "aluno" and "estudante" means student. You can use both of them to mention who takes classes and who teaches classes. According to the dictionary: ALUNO means: to whom learns education/instructions from another. And ESTUDANTE: who studies; who takes classes in a school. For example: Os alunos da quinta série ficaram sem recreio. Os estudantes se reuniram com a professora para reivindicar seus direitos. Did you understand? You can use both.

isto é muito relativo, muitas pessoas podem ter opiniões diferentes sobre isto, nas minha Opinião Estudante--> É aquele que somente assisti a aula (Meio que Obrigado) e Aluno --> É aquele que esta interessado em estudar e esta prestando atenção na aula.