Can you please explain what kind of speaking about women that permissible and which kind is haram?,
I mean like talking about a women's beautiness with my friends, or a women's attitude, or maybe just her general physical descriptions.

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad, is His slave and Messenger.

The basic principle regarding talking about women is that it is permissible, as is the case with what is reported in the Sunnah about women being a source of Fitnah (temptation) and that whenever a woman goes outdoors, Satan beautifies her in men’s eyes to use her as a means to lure them into Fitnah and the like. If the talk about women involves what is forbidden under the Sharee‘ah, then it is deemed prohibited. This applies to talking about women in a manner that leads to temptation and the promotion of immorality. Let us take as an example what was stated in the Hadeeth on the authority of ‘Abdullaah ibn Mas‘ood who narrated that the Prophet said: “A woman should not look at or touch another woman and then describe her to her husband in such a way as if he was actually looking at her.” [Al-Bukhari and Muslim] This forbiddance of describing a woman was interpreted by scholars to mean giving a detailed description of a specific woman, as stated in Mirqaat Al-Mafaateeh Sharh Mishkaat Al-Masaabeeh: “It means that she describes the softness of her skin and the tenderness of her body to her husband as if he is actually looking at her. Accordingly, his heart gets attached to this woman and temptation occurs as a result. What is actually forbidden is the description mentioned in the Hadeeth.” [End of quote]

However, there is nothing wrong with talking about the beauty of unnamed or unknown women as long as there is no obscene or vulgar language used. In his famous poem “Baanat Su‘aad”, Ka‘b ibn Zuhayr mentioned and highly praised the beauty of a woman to whom he gave the name “Su‘aad”, and the Prophet did not disapprove of that.

We would like to point out that the Muslims should devote their times and gatherings to what benefits them with regard to their religiosity and worldly affairs. Abu Hurayrah narrated that the Messenger of Allah said: “Be keen on doing what benefits you.” [Muslim] Sahl ibn Sa‘d As-Saa‘idi narrated that the Prophet, sallallaahu ‘alayhi wa sallam, said: “Allah, The Exalted, loves noble matters and hates trivial ones.” [At-Tabaraani and Al-Bayhaqi in Shu‘ab Al-Eemaan]

Allah Knows best.