A saber

= namely, viz, to wit
Ex: Then, in the 1930s extraterrestrial radio signals were detected, and during the last four decades a whole new intellectual area of science has developed, namely radio astronomy. Ex: There are two main categories of relationship, viz semantic and syntactic relationships. Ex: At dinner, he was to learn several other things as well, to wit: that he was one of three people being brought in for an initial and then a second interview; that they had been very impressed by his credentials; and that no one from the Halvorsen staff had applied for the position.

das heißt;das heisst

yani

specifically (namely)

das heißt