The word 学霸 (xué bà) originally referred to a personage who has had or has a great influence in academic circles, such as Einstein. 霸 (bà) in Chinese has the meaning of extremely powerful or authoritative. Nowadays 学霸 (xué bà) is an internet term and refers to someone both intelligent and diligent, someone with extremely good results at study.
The reason that 学霸 (xué bà) has become popular on the internet is because many 学霸 (xué bà) have grabbed people's attention on the internet. For example, recently two 学霸 (xué bà) twins have become famous on the internet. Both of them are students at Tsinghua University. The video of their oral defense of the application for a university scholarship went viral on the internet and caused many netizens to cry out 'wow' in awe because they not only have excellent results but they have shown themselves to be outstanding in many other fields besides study.
There is another 学霸 (xué bà) who has become hot news on the internet. He's also a Tsinghua University student. He also became famous through his video of his scholarship application. It is a fact that in China students need to sit a university entrance examination called the 'gaokao'. The student with the best mark in the 'gaokao' is called the 'zhuangyuan'. This 学霸 (xué bà) was once the 'zhuangyuan' in his province. At high school he received many awards in mathematics and physics. At university this 学霸 (xué bà) studied for two degrees at the same time. In the twenty subjects that he took, except for 1 score of 98 and 4 scores of 99, in the other subjects he attained the maximum score of 100. His successes led netizens to worship and admire him, with everyone calling him 学神 (xué shén) (study god), a meaning about the same as 学霸 (xué bà).
There is another word that has become popular on the internet, called 学渣 (xué zhā). The opposite of 学霸 (xué bà), 学渣 (xué zhā) refers to someone that doesn't love study with relatively poor results. I suppose all of you have met quite a few 学霸 (xué bà) and 学渣 (xué zhā)?