What is section 124a of IPC ?

The Apex court on Tuesday protected Congress leader Shashi Tharoor and six journalists from arrest in multiple sedition FIRs registered against them for allegedly tweeting and sharing unverified news that a young farmer died at the hands of the police during the tractor rally on Republic Day parade.
A Bench led by Chief Justice of India Sharad A. Bobde stayed any coercive action or arrest against Mr. Tharoor, Rajdeep Sardesai, Anant Nath, Paresh Nath, Vinod K. Jose, Mrinal Pande and Zafar Agha. The Bench scheduled a hearing on merits after a fortnight.
“Section 124A IPC (Sedition) has been added for their tweets [in the FIRs]... Protect them during the period of the notice,” Mr. Sibal urged the court.
Source : The Hindu
What is section 124a?
101 [124A. Sedition.—Whoever, by words, either spoken or written, or by signs, or by visible representation, or otherwise, brings or attempts to bring into hatred or contempt, or excites or attempts to excite disaffection towards, 102 [***] the Government established by law in 103 [India], [***] shall be punished with 104 [imprisonment for life], to which fine may be added, or with imprisonment which may extend to three years, to which fine may be added, or with fine. Explanation 1.—The expression “disaffection” includes disloyalty and all feelings of enmity. Explanation 2.—Comments expressing disapprobation of the measures of the Government with a view to obtain their alteration by lawful means, without exciting or attempting to excite hatred, contempt or disaffection, do not constitute an offence under this section. Explanation 3.—Comments expressing disapprobation of the administrative or other action of the Government without exciting or attempting to excite hatred, contempt or disaffection, do not constitute an offence under this section.]
Source : Indiankanoon