As mentioned above, CCF is evaluated by authoritative people in the computer field, while SCI is divided according to journal impact factors. SCI has a wider scope and covers more disciplines, while CCF focuses on the computer field. It can be understood that the criteria for judging are different, but whether it is ABC class of SCI or CCF, the gold content is very high. In fact, CCF's rating standard is not completely scientific ~ if it is not C-level, it will definitely be worse than B-level ... This rating is also the result of many big players in the industry, and each big player's views and ideas cannot be absolutely the same. So there is no need to entangle ABC class too much.