A lease commitment is a binding promise to pay for the use of something, such as office space, a warehouse, a data center, vehicles or equipment, over a period of time. Under current accounting standards, most leases that have started appear on the balance sheet as a liability for the payments owed and an asset for the right to use the property.
Leases that have been signed but have not yet begun are different. They are generally not recorded on the balance sheet until the asset is made available, but they must be disclosed in the notes as commitments. For a company building out infrastructure, these can be large.
Commitments matter because they are fixed claims on future cash, similar to debt, although they are not always described as such. They reduce flexibility if business slows down.
Read the lease note for the total payments, the schedule, the terms and the amount of leases not yet started, and include them when you assess how much the company owes.