Sthanakwasi Jain monks belong to the Śvetāmbara Sthanakwasi tradition, which arose from the non-idol-worshipping reform movement in Jainism.

Simple lineage overview

• Jain Dharma

- Śvetāmbara - Sthanakwasi - Monastic lineage of Sthanakwasi sadhus and sadhvis - Later, from this reform stream, Terapanth also developed

Main beliefs of Sthanakwasi monks

• They do not worship idols (murtipuja).
• They practice strict renunciation, ahimsa, fasting, and scriptural study.
• They usually perform devotion in sthanaks (prayer halls), not temples.

Historical root

Sthanakwasi tradition is generally traced to the reform movement associated with Lonka Shah, which emphasized the importance of non-idolatry and scriptural purity.

If you want, I can also give the full monk lineage tree of the Sthanakwasi tradition in a simple chart form.