Harriet Jacobs and Frederick Douglass both viewed slavery as an absolute evil, and they each portray slavery as an utterly corrupting influence on both the enslaved and the enslavers. For both, freedom meant the absence of slavery, and this is why both fled to the North, to escape their condition. Each also mentions literacy as a source of freedom. But beyond this, they view freedom in slightly different ways, because their enslavement experiences were different. As a young woman, Harriet Jacobs ("Linda" in the book) experienced the relentless overtures of Dr. Flint, her owner, who continually attempts to seduce and even sexually assault her. She is trapped between Dr. Flint and his wife, who blames her for the doctor's overtures, and as she enters into sexual relationships, and has children to escape his attentions, and she even receives the condemnation of her own grandmother.
So desperate is Jacobs to escape this situation that she hides in the attic of her grandmother's house for seven years. As she says in Chapter Ten in commenting on her affair with a white man (not Dr. Flint,) "there is something akin to freedom in having a lover who has no control over you, except that which he gains by kindness and attachment." For an enslaved woman, then, having a modicum of control of one's own heart and body was close to freedom.
For Douglass, too, control over his body is "something akin to freedom," and this is why he puts so much emphasis on his fight with the overseer. But for an enslaved woman, "freedom" had a dimension it did not have for a man like Douglass. Also, her freedom was not complete until she had secured freedom for her children, an issue Douglass did not have.