sign up和sign in的区别：
1、sign up 的意思是注册报名， 跟…签订合同。
2、sign in 的意思是登录，签到，通过签字（使）取得入场权，画到。
拓展资料
sign up的用法
1、He signed up as a steward with P& O Lines
他签约了P&O航运公司，成为了一名乘务员。
2、He saw the song's potential, and persuaded the company to sign her up.
他看到了这首歌的潜力，就说服公司和她签约。
3、Lisa: I'll sign up tomorrow.
丽莎：我明天就要去报名了。
4、Can I sign up for this course in advance?
我能事先申请上这一课程吗？
5、Maybe you and me should sign up.
也许你和我也可以去登记。
sign in的用法
1、I signed in and crunched across the gravel to my room.
我签到后嘎吱嘎吱走过石子路来到我的房间。
2、All the participants were required to sign in as they entered the hall to attend the meeting.
出席会议的人在进入大厅前均须签到。
3、You can sign in right there.
你可以就签在那。
4、I put the negation sign in front of that.
我在前面写上否定的标志。
5、The flow then continues as in the Sign in process.
然后该流将像在“登录”流程中那样继续进行。