I still have plenty of information to go over before getting into actual characters, but I kind of got tired of writing all of it and was impatient to get into actual content.
Here are the two characters 月(yuè – moon) and 肉(ròu – meat) in the 說文解字(I’ll be using this dictionary a lot to cite character etymologies).
Here you can see the slight differences in 小篆(Xiǎo Zhuàn, small seal script). As semantic components in traditional Chinese they are still different, 月 and ⺼.
During the simpification process the “meat” component disappeared and was replaced by “moon”. This small simplification makes understanding 漢字 much more difficult since there are many more characters that use the 肉 component than the 月 component. If you look at almost any body part in Chinese, you will almost always see 肉 as a part of the character. In simplified it is 月 leading you to believe the character has something to do with light. (Left is traditional, right is simplified)
yáo (meat dishes)- Here the top component is the phonetic value, 爻(yáo), and 肉 is the semantic component.
yǒu (to have, exist) – Here the top component, a form of 又(yòu), gives us our pronunciation and then there is 月. I won’t go into the etymology of this one as it is rather difficult and somewhat disputed upon.
xiào (to resemble) – On top we have 小(xiǎo) the phonetic portion, and on bottom 肉, the meaning.
These two semantic components also have variants that show still show the differences in traditional characters.
rán (correct, thus) – Here we have 肰(rán) the phonetic component, its meaning is “dog meat” so if you know that, then you know that it uses 肉 and not 月. As for the semantic part, 灬 is a form of 火(fire); the original meaning for the character was “to burn”, but now through rebus the meaning has changed and a new character was created for “to burn”, 燃.
wàng (full moon, to hope) – Here we have the the meaning coming from 亡(deceased, to be gone); the meaning of the character comes from the story of a prince who was exiled (出亡-to go into exile) and the king’s longing (wishing) that he be back. The phonetic part comes from a portion of 朢(wàng).
As you can see there is a rather important difference between the two. The 肉 semantic component has been transformed into 月 in most cases.
Understanding a 漢字’s etymology is very important in understanding its meaning, with simplified characters, the meaning has almost always been lost.
Here are three short explanations from Taiwan’s Ministry of Education’s website on the matter.