There’s has always been confusion between SCI, SCIE and SCImago journals. Here’s how you differentiate them:
SCI stands for Science Citation Index and was formed by the Institute for Scientific Information (ISI) and created by Eugene Garfield. It is now owned and maintained by Thomson Reuters.
SCIE stands for Science Citation Index Expanded is a bibliographic database. It is created by Eugene Garfield and owned by Thompson Reuters as well.
SCImago Journal is named after the SCImago Journal Rank (SJR) indicator. This index is based on SCOPUS database.