Neville, IITFT:
There is a dispute in the Mishna Sotah 20a whether one is even allowed to teach Torah to women at all. The argument against the teaching of Torah to women states that if one does so, it is like teaching them Tiflus. Rashi comments that Tiflus means lechery, meaning the study of Torah will lead women to immorality. Rashi then cites the famous story of Bruriah, one of the greatest female scholars in Jewish history to prove his point. One day, Bruriah ridiculed the Gemara (in Kidushin 80b) which states that that women are lightheaded. Rabbi Meir, her husband, ordered his student to test Bruriah’s strength and try to seduce his wife. Bruriah caved in and when she realized what she had done, she hung herself.
Thus Rashi’s argument is that women’s minds are not meant for serious Torah learning. The Rambam agrees with Rashi’s take. Rambam also adds that when the chachamim had said, “He who teaches his daughter Torah, is as if he taught his daughter tiflus,”only applies to the oral law. The Rambam says that a man should not teach his daughters written law but if he does, it is not considered tiflus. The Shulchan Aruch follows this approach of Rambam.
The conclusion is that there are four areas within this law, as per Shulchan Aruch:
1. Women may not learn the Oral Torah
2. Women may learn the simple meaning of the Written Torah
3. Women may not learn the Written Torah in depth
4. Women must learn the laws that apply to them
Note that Rashi, Ramban, etc. are part of Torah Shebalpeh.