Is it keep abreast of or with?

side by side; beside each other in a line: They walked two abreast down the street. equal to or alongside in progress, attainment, or awareness (usually followed by of or with): to keep abreast of scientific developments; keeping abreast with the times.

What is to keep abreast of mean?

Stay or cause to stay up-to-date with, as in He's keeping abreast of the latest weather reports, or Please keep me abreast of any change in his condition. This term alludes to the nautical sense of abreast, which describes ships keeping up with each other. [