If I'm not wrong, そうだ is used when you hear something from someone else and you are trying to relay it forward to another person. For example, you hear なつみさん say that 高田さん is sick. So when the teacher asks you wheres 高田さん、 you reply: "高田さんは病気で休んでいるそうです". But what about ようだ? What if you replaced it and said "高田さんは病気で休んでいるようです"? What difference does it make?
Ive also heard that ようだ is used when you notice something. For example, you see your friend 若宮 laughing with your elder brother, and you are shocked. You silently think to yourself: "若宮さんは兄貴と仲がいいようですね..." Similarly, does it make a difference if i replace ようです here with そうです?
All in all, what are the differences and similarities between ようだ and そうだ?