サインオン

サ

イ

ン

オ

ン

Meanings

1

noun, noun or participle which takes 'suru'

sign on; log in

computing

Computing term for logging into a system or service. Often used as a noun or with する.

サインオン

Variant with interpunct; less common in running text.

サイン・オン

ログイン
ログイン is the more common general term for logging in; サインオン is used in specific computing contexts, sometimes implying a session start.
サインイン
サインイン is a synonym often used interchangeably, though サインオン may emphasize connecting to a network or service.

Borrowed from English 'sign on', used in computing contexts.