Reflexive verbs in Russian are used to indicate the concept of ‘self’. For example ‘I dressed myself’. Notice in this sentence that the subject and the object are actually the same person.
When this happens in English we use the word ‘-self’, or simply omit the object. In Russian you simply add “ся” or “сь” to the verb. You can think of this as being a short way to write “себя” (self).
The reflexive form is also used for intransitive verbs. Intransitive verbs are those verbs which have a subject, but no object.