Okaasan お母さん

The様 suffix and the o 御 prefix are only sometimes written with. So, for example,can also be written お母様 or 御母様.

The word okaachan means the same thing as okaasan, "mother."

The difference between okaasan and okaachan お母ちゃん is that okaachan is a cozier word. It can imply a more friendly, relaxed, or intimate relationship between the speaker and the okaachan.

Otousama

The word okaasama means the same thing as okaasan, "mother."

The difference between okaasan and okaasama お母さま is that okaasama has more reverence. In anime, this often implies that the character is from a traditional family (often rich $$$) which believes children must address their parents, grandparents, etc. with respect.

In some cases, it can imply the speaker has admiration or esteem toward their mother.

Kaasan, Kaachan, Kaasama