what is hashing ? can anyone explain me ? I searched google but cannt understand :(

i solved about 50 prblms on codeforces.all them was A prblm.i took about 5 months to solve this.moreover,whenever i was failed to solve any prblm,i often looked others submission. now i wanted to solve b,c,d,e(the prblms seem very hard for me).as, i wanted to solve morer and more, so,what should i do now ? as, i dnt know about algo, so now should i try to know about algos and other theory or continue doing the same as before?