Hi @worriedmum thats a timely question! Self-isolation is a public health measure to reduce spread, that requires the at-risk individual (whether from travel or possible exposure) to practice social responsibility by remaining at home and avoiding contact with others. This is the overarching concept whereby stay home notice (SHN) is a subset.

It has been broken down to 3 incremental levels within Singapore for the current outbreak - leave of abscence (LOA), SHN and Quarrantine. More on that at this link:  https://www.moh.gov.sg/docs/librariesprovider5/2019-ncov/moh-health-advisory-for-persons-issued-stay-home-notice-(updated-13-mar)-(1530h).pdf

Unlike LOA, SHN has a legal element whereby relevant individuals are obligated to stay within their home premises at all times except for emergencies. Ultimately, you’d be doing your friends, loved ones and neighbours a solid by not exposing them if in case you develop the illness. Also, failure to comply may result in prosecution under the infectious disease act.

Family members are not needed to isolate as well, but are recommended to take precautions at home to avoid exposure, and to seek esrly medical attention should you feel unwell. More on that at this link: https://www.channelnewsasia.com/news/singapore/covid-19-faq-stay-home-notice-what-you-need-to-know-coronavirus-12542892